diff --git a/README.md b/README.md
index d3341b7..59ae7f0 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ SummerCMS is a content management framework for Go, inspired by WinterCMS. An ap
 ## Requirements
 
 - Go 1.27.
-- PostgreSQL 16 for any application that uses the data layer ([lagoon](modules/lagoon/README.md)). lagoon currently requires the database's default locale to be ICU `pl-PL`; see [Known issues](#known-issues).
+- PostgreSQL 16 for any application that uses the data layer ([lagoon](modules/lagoon/README.md)).
 - Node.js 22.6 or newer, only when working on the admin SPA in `admin/`.
 - Docker, only for the integration tests that start PostgreSQL or Mailpit containers through testcontainers-go.
 
@@ -32,10 +32,10 @@ summer build          # generates plugins.gen.go and main.go, writes bin/hello
 
 The `migrate`, `migrate:status`, `migrate:rollback`, `serve` and admin commands open PostgreSQL, so they need more configuration. Configuration comes from YAML files in `config/`, and any key can be overridden with a `SUMMER_`-prefixed environment variable in which a double underscore separates path segments (see [compass](modules/compass/README.md)):
 
-1. Create a PostgreSQL 16 database with the locale lagoon checks for:
+1. Create a PostgreSQL 16 database:
 
    ```sql
-   CREATE DATABASE hello TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL';
+   CREATE DATABASE hello;
    ```
 
 2. Add the request body limits that `serve` and `route:list` require. The example does not ship them yet, and surf needs numeric values, which the string-valued environment overlay cannot supply. Create `config/http.yaml` in `examples/hello`:
@@ -64,7 +64,6 @@ The `migrate`, `migrate:status`, `migrate:rollback`, `serve` and admin commands
 ### Known issues
 
 - `examples/hello` has no `http.body_limits` configuration, so `serve` and `route:list` fail with `surf: config http.body_limits.default_bytes is required` until you add it as in step 2. The same gap makes the example's `TestTypedItemRoute` fail.
-- lagoon refuses any database whose default locale is not ICU `pl-PL`.
 - The committed `examples/hello/main.go` is older than what `summer build` generates now, so building the example (or running its tests, which build it) leaves that file modified. Restore it with `git checkout -- examples/hello/main.go` if you do not intend to commit it.
 
 ## Repository layout
diff --git a/docs/database/models.md b/docs/database/models.md
index 787d36a..b3f1ae8 100644
--- a/docs/database/models.md
+++ b/docs/database/models.md
@@ -8,7 +8,7 @@ order: 10
 
 A WinterCMS model extends Eloquent and describes its behaviour with properties such as `$fillable`, `$hidden` and `$jsonable`. A SummerCMS model is a plain GORM struct in the plugin's `models` package, and [lagoon](../../modules/lagoon/README.md) supplies the Eloquent conventions that GORM does not have: allow-listed mass assignment, JSON and encrypted columns, Laravel-style validation and pagination.
 
-The data layer supports PostgreSQL only. `lagoon.Open` refuses a database whose default collation is not the ICU `pl-PL` locale (`lagoon.CheckLocale`), so text ordering is the same in every query without a `COLLATE` clause. Create the database with that locale, as shown in [Installation](../setup/installation.md).
+The data layer supports PostgreSQL only and puts no requirement on the database's default locale. A list that must sort text in one language's order passes a collation to `lagoon.OrderBy`, as described in [Queries and pagination](queries-and-pagination.md#sorting-with-a-collation).
 
 ## Defining a model
 
diff --git a/docs/database/queries-and-pagination.md b/docs/database/queries-and-pagination.md
index 005c344..3256fca 100644
--- a/docs/database/queries-and-pagination.md
+++ b/docs/database/queries-and-pagination.md
@@ -39,7 +39,32 @@ fmt.Println(err)
 
 Answer the error as a validation failure (422). The column must match an allow-list entry exactly, so list the qualified name (`acme_blog_posts.title`) when the query joins another table.
 
-`lagoon.OrderBy` never adds a `COLLATE` clause. Text sorts by the database's ICU `pl-PL` default collation, which lagoon checks when it connects.
+## Sorting with a collation
+
+Text sorts by the database's default collation unless you pass `lagoon.Collate`. A list that must follow one language's alphabet (Polish puts Ł between L and M, for example) passes `lagoon.Collate("pl-x-icu")`, and `lagoon.OrderBy` adds a `COLLATE` clause for that column only. ICU collations named `<language>-x-icu` exist in any PostgreSQL built with ICU support, which includes the official Docker images, so the database needs no special locale:
+
+```go src=modules/lagoon/example_test.go#ExampleCollate
+// A dry-run handle shows the SQL without a database.
+db, _ := gorm.Open(postgres.New(postgres.Config{DSN: "host=127.0.0.1"}), &gorm.Config{DryRun: true, DisableAutomaticPing: true})
+allowed := []string{"title", "views"}
+
+// Polish alphabetical order, whatever the database's default locale.
+q, err := lagoon.OrderBy(db.Model(&Post{}), "title", "asc", allowed, lagoon.Collate("pl-x-icu"))
+if err != nil {
+	fmt.Println(err)
+	return
+}
+var posts []Post
+fmt.Println(q.Find(&posts).Statement.SQL.String())
+
+_, err = lagoon.OrderBy(db, "title", "asc", allowed, lagoon.Collate(`pl-x-icu" ASC, (SELECT 1) --`))
+fmt.Println(err)
+// Output:
+// SELECT * FROM "acme_blog_posts" WHERE "acme_blog_posts"."deleted_at" IS NULL ORDER BY title COLLATE "pl-x-icu" ASC
+// lagoon: order collation "pl-x-icu\" ASC, (SELECT 1) --" is not a valid collation name
+```
+
+The collation name is validated (ASCII letters, digits, `_`, `-`, `.` and `@`, at most 63 bytes) and quoted as an identifier; anything else is an error, and no SQL is built. An index only helps that ORDER BY when it is built with the same collation.
 
 ## Pagination
 
diff --git a/docs/examples/blog/postgres_test.go b/docs/examples/blog/postgres_test.go
index 99e4ef5..f5cc0a4 100644
--- a/docs/examples/blog/postgres_test.go
+++ b/docs/examples/blog/postgres_test.go
@@ -100,10 +100,9 @@ func stopPostgres() {
 	}
 }
 
-// icuDatabase creates a database for one test with the ICU pl-PL locale
-// lagoon requires, and drops it when the test ends. It returns the pool
-// opened on it and its DSN.
-func icuDatabase(t *testing.T) (*sql.DB, string) {
+// testDatabase creates a database for one test and drops it when the test
+// ends. It returns the pool opened on it and its DSN.
+func testDatabase(t *testing.T) (*sql.DB, string) {
 	t.Helper()
 	if testing.Short() {
 		t.Skip("requires testcontainers postgres")
@@ -113,7 +112,7 @@ func icuDatabase(t *testing.T) (*sql.DB, string) {
 	}
 	name := "blog_" + strings.ToLower(strings.NewReplacer("/", "_", "-", "_").Replace(t.Name()))
 	quoted := `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
-	if _, err := pgAdmin.ExecContext(t.Context(), `CREATE DATABASE `+quoted+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`); err != nil {
+	if _, err := pgAdmin.ExecContext(t.Context(), `CREATE DATABASE `+quoted+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil {
 		t.Fatalf("create %s: %v", name, err)
 	}
 	u, err := url.Parse(pgDSN)
@@ -133,11 +132,11 @@ func icuDatabase(t *testing.T) (*sql.DB, string) {
 	return db, dsn
 }
 
-// migrated activates acme.blog, migrates a fresh ICU database and publishes
+// migrated activates acme.blog, migrates a fresh database and publishes
 // it on the application, as the serve command does at start-up.
 func migrated(t *testing.T) (*backpack.App, party.Plugin, *gorm.DB) {
 	t.Helper()
-	sqlDB, _ := icuDatabase(t)
+	sqlDB, _ := testDatabase(t)
 	gdb, err := lagoon.Use(t.Context(), sqlDB)
 	if err != nil {
 		t.Fatalf("lagoon.Use: %v", err)
diff --git a/docs/plugins/testing.md b/docs/plugins/testing.md
index 5122a70..1a1f1d3 100644
--- a/docs/plugins/testing.md
+++ b/docs/plugins/testing.md
@@ -31,10 +31,9 @@ Most plugin code runs without a database. Build a container with `backpack.New`,
 
 ## Database tests
 
-SummerCMS supports PostgreSQL only, so database tests run against real PostgreSQL rather than an SQLite stand-in. The framework's own tests start a `postgres:16-alpine` container through testcontainers-go and create the database with the ICU `pl-PL` locale that lagoon checks for when it connects. Follow the same pattern in plugin tests:
+SummerCMS supports PostgreSQL only, so database tests run against real PostgreSQL rather than an SQLite stand-in. The framework's own tests start a `postgres:16-alpine` container through testcontainers-go and create a fresh database per test. Follow the same pattern in plugin tests:
 
 - skip the test when `testing.Short` reports true;
-- create the database with `LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`, or lagoon refuses the connection;
 - migrate a fresh database per test with `lagoon.Migrate`, so tests do not depend on each other.
 
 Docker must be running for these tests.
diff --git a/docs/setup/installation.md b/docs/setup/installation.md
index 0203b90..d43d94b 100644
--- a/docs/setup/installation.md
+++ b/docs/setup/installation.md
@@ -11,7 +11,7 @@ SummerCMS is a Go module. An application requires it, lists its plugins in a `su
 ## Requirements
 
 - Go 1.27.
-- PostgreSQL 16 for any application that uses the data layer. The database's default locale must be the ICU `pl-PL` locale, which lagoon checks when it connects.
+- PostgreSQL 16 for any application that uses the data layer.
 - Docker, only for the integration tests that start PostgreSQL or Mailpit containers.
 
 You do not need Node.js to build an application or these docs. It is needed only when you work on the admin SPA itself.
@@ -74,10 +74,10 @@ summer build
 
 ## Create the database
 
-The commands that touch data open PostgreSQL. Create a database with the locale lagoon checks for:
+The commands that touch data open PostgreSQL. Create a database for the example:
 
 ```sql
-CREATE DATABASE hello TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL';
+CREATE DATABASE hello;
 ```
 
 ## Configure the application
@@ -117,7 +117,6 @@ From the application directory, `summer migrate`, `summer migrate:status` and `s
 > Known issues in the current framework:
 >
 > - `examples/hello` ships no `http.body_limits` configuration, so `serve` and `route:list` fail with `surf: config http.body_limits.default_bytes is required` until you add `config/http.yaml` as shown above. The same gap makes the example's `TestTypedItemRoute` fail.
-> - lagoon refuses any database whose default locale is not ICU `pl-PL`.
 > - The committed `examples/hello/main.go` is older than what `summer build` generates now, so building the example leaves that file modified. Restore it with `git checkout -- examples/hello/main.go` if you do not intend to commit it.
 
 ## Next steps
diff --git a/modules/beachcomber/postgres_test.go b/modules/beachcomber/postgres_test.go
index 46d8eb1..84b4e8f 100644
--- a/modules/beachcomber/postgres_test.go
+++ b/modules/beachcomber/postgres_test.go
@@ -58,9 +58,6 @@ func startBeachcomberPostgres(ctx context.Context) error {
 		postgres.WithUsername("beachcomber"),
 		postgres.WithPassword("beachcomber"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		return err
@@ -106,14 +103,14 @@ func adminDB(t *testing.T) *sql.DB {
 	return bcSQL
 }
 
-// migratedDB returns a dedicated ICU pl-PL database migrated with
+// migratedDB returns a dedicated database migrated with
 // lagoon.Migrate (River v7 and summer_jobs) plus its DSN.
 func migratedDB(t *testing.T) (*sql.DB, string) {
 	t.Helper()
 	admin := adminDB(t)
 	ctx := t.Context()
 	name := fmt.Sprintf("beachcomber_%d", dbSeq.Add(1))
-	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`); err != nil && !strings.Contains(err.Error(), "already exists") {
+	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil && !strings.Contains(err.Error(), "already exists") {
 		t.Fatalf("create %s: %v", name, err)
 	}
 	dsn, err := dsnWithDB(bcDSN, name)
diff --git a/modules/bouncer/phase07_coverage_test.go b/modules/bouncer/phase07_coverage_test.go
index f005fe6..fa0bb45 100644
--- a/modules/bouncer/phase07_coverage_test.go
+++ b/modules/bouncer/phase07_coverage_test.go
@@ -8,7 +8,6 @@ import (
 	"time"
 
 	_ "github.com/jackc/pgx/v5/stdlib"
-	"github.com/testcontainers/testcontainers-go"
 	"github.com/testcontainers/testcontainers-go/modules/postgres"
 )
 
@@ -70,9 +69,6 @@ func TestPostgresBlacklistConcurrent(t *testing.T) {
 		postgres.WithUsername("bl"),
 		postgres.WithPassword("bl"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		t.Fatal(err)
diff --git a/modules/cabana/auth_test.go b/modules/cabana/auth_test.go
index b17697b..9203a24 100644
--- a/modules/cabana/auth_test.go
+++ b/modules/cabana/auth_test.go
@@ -28,7 +28,6 @@ import (
 	"git.golem15.com/golem15/summercms/modules/party"
 	"git.golem15.com/golem15/summercms/modules/surf"
 	_ "github.com/jackc/pgx/v5/stdlib"
-	"github.com/testcontainers/testcontainers-go"
 	"github.com/testcontainers/testcontainers-go/modules/postgres"
 	"gorm.io/gorm"
 )
@@ -332,9 +331,6 @@ func adminGorm(t *testing.T) *gorm.DB {
 			postgres.WithUsername("cabana"),
 			postgres.WithPassword("cabana"),
 			postgres.BasicWaitStrategies(),
-			testcontainers.WithEnv(map[string]string{
-				"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-			}),
 		)
 		if err != nil {
 			adminErr = err
diff --git a/modules/conga/postgres_test.go b/modules/conga/postgres_test.go
index 8975e96..274b81d 100644
--- a/modules/conga/postgres_test.go
+++ b/modules/conga/postgres_test.go
@@ -61,9 +61,6 @@ func startCongaPostgres(ctx context.Context) error {
 		postgres.WithUsername("conga"),
 		postgres.WithPassword("conga"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		return err
@@ -109,14 +106,14 @@ func adminDB(t *testing.T) *sql.DB {
 	return congaSQL
 }
 
-// migratedDB returns a dedicated ICU pl-PL database migrated with
+// migratedDB returns a dedicated database migrated with
 // lagoon.Migrate (River v7 and summer_jobs) plus its DSN.
 func migratedDB(t *testing.T) (*sql.DB, string) {
 	t.Helper()
 	admin := adminDB(t)
 	ctx := t.Context()
 	name := fmt.Sprintf("conga_%d", dbSeq.Add(1))
-	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`); err != nil && !strings.Contains(err.Error(), "already exists") {
+	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil && !strings.Contains(err.Error(), "already exists") {
 		t.Fatalf("create %s: %v", name, err)
 	}
 	dsn, err := dsnWithDB(congaDSN, name)
diff --git a/modules/lagoon/README.md b/modules/lagoon/README.md
index c910779..d83acb1 100644
--- a/modules/lagoon/README.md
+++ b/modules/lagoon/README.md
@@ -15,11 +15,10 @@ Postgres data layer: the shared GORM connection, per-plugin migrations, model he
 - One shared pool: `lagoon.Open`, `lagoon.Use` and `lagoon.OpenFromApp` return a `*sql.DB` and a `*gorm.DB` built on that same pool; `lagoon.Publish` makes both available on the `backpack.App`.
 - Database-ready hooks: `lagoon.OnDatabase` runs a callback with the pool and GORM handle as soon as the database is published, immediately when it already is, otherwise when `lagoon.Publish` runs. Plugins register GORM callbacks through it from Boot, which runs before the `serve` command publishes the database.
 - After-commit work: `lagoon.Transaction` runs a function in a transaction and then the callbacks registered with `lagoon.AfterCommit`, in order, only after the commit succeeds; a nested `lagoon.Transaction` is a savepoint whose callbacks are dropped with it when it fails. A nested `lagoon.Transaction` must be given the outer transaction's handle: given a root handle it returns an error without running its function, rather than open an independent transaction whose callbacks would wait on the outer one. A single-statement write for which GORM opens its own implicit transaction runs its callbacks from `lagoon:after_commit` once GORM commits, and never when the write fails. A callback registered inside a foreign plain GORM transaction is unsafe because Lagoon cannot observe its commit, so `lagoon.AfterCommit` warns and skips it. Outside a transaction, callbacks run immediately. The handle a supported callback receives always has an empty statement on the connection its work belongs to. A panicking callback is logged and never turns a committed write into an error.
-- Database check at connect time: `lagoon.CheckLocale` refuses a database whose default collation is not the ICU `pl-PL` locale, so ordering matches the database default without per-query `COLLATE`.
 - Per-plugin migrations: `lagoon.Migrate` runs the framework's `system_files` set (`attach.Migrations`), backend admin identity set (`lagoon.BackendAdminMigrations`) and job-queue set (`lagoon.QueueMigrations`: River's schema pinned at `lagoon.RiverSchemaVersion`, then the `lagoon.JobsTable` record table, under the `lagoon.QueueHistoryID` history), then every `pact.HasMigrations` set in plugin activation order, each in its own `summer_migrations_<plugin_id>` history table (`lagoon.HistoryTableName`). `lagoon.RollbackLast` and `lagoon.Status` cover rollback and history.
 - Mass assignment: `lagoon.Fill` copies only allow-listed keys onto a model by GORM column name and silently drops the rest, logging each dropped key once outside production. A `json.Number` (from a decoder using `UseNumber`) fills integer, unsigned and float fields. A value that does not fit its column (a fraction, an exponent or an overflow for an integer field, or a value of the wrong type) is a `lagoon.FillTypeError` naming the key, so a caller can answer it as a validation failure on that field. `lagoon.HasFillable` and `lagoon.HasHidden` are the Go forms of `$fillable` and `$hidden`.
 - Validation: `lagoon.Validate` accepts Laravel-style rule strings (`required`, `nullable`, `integer`, `numeric`, `between`, `min`, `max`, `in`, `unique`, `boolean`, `email`, `confirmed`, `different`, `mimes`) and returns a field-to-messages map, translated through phrasebook when a translator is given. Unknown rule tokens are an error.
-- Safe ordering: `lagoon.OrderBy` appends an ORDER BY only for an allow-listed column and an `asc` or `desc` direction.
+- Safe ordering: `lagoon.OrderBy` appends an ORDER BY only for an allow-listed column and an `asc` or `desc` direction, and `lagoon.Collate` adds a validated `COLLATE` clause for language-specific text order (for example the ICU collation `pl-x-icu`); lagoon puts no requirement on the database's default locale.
 - Pagination: `lagoon.Paginate` builds a `lagoon.Page` with `data` and `meta` (`current_page`, `last_page`, `per_page`, `total`).
 - Column types: `lagoon.Encrypted` stores AES-256-GCM ciphertext under a key derived from `app.key`, decrypts with previous keys during rotation, and always redacts itself in JSON and string output; `lagoon.Jsonable` stores JSON as TEXT and keeps SQL NULL distinct from an empty value.
 - Lifecycle and relations: hook interfaces matching GORM's native method names (`lagoon.HasBeforeCreate`, `lagoon.HasBeforeSave`, `lagoon.HasBeforeDelete`, `lagoon.HasAfterDelete`) plus `lagoon.HasBeforeValidate`; `lagoon.WithSoftDeleteCascade` runs a cascade inside the parent delete; `lagoon.RegisterJoinTable` wires pivot models with business columns.
@@ -110,15 +109,14 @@ func (p *Plugin) Migrations() []*gormigrate.Migration {
 | Identifier | Description |
 |------------|-------------|
 | `lagoon.OpenFromApp` | Opens the shared pool from `database.dsn` and publishes the `app.key` encryption keys. |
-| `lagoon.Open` | Opens and pings a DSN, checks the locale and returns the pool plus a GORM handle on it. |
-| `lagoon.Use` | Returns a GORM handle on an existing pool after the same checks. |
+| `lagoon.Open` | Opens and pings a DSN and returns the pool plus a GORM handle on it. |
+| `lagoon.Use` | Returns a GORM handle on an existing pool after a ping. |
 | `lagoon.Publish` | Stores the pool and GORM handle on the `backpack.App`, then runs the callbacks queued by `lagoon.OnDatabase`. |
 | `lagoon.OnDatabase` | Runs a callback with the pool and GORM handle once the database is published. |
 | `lagoon.Transaction` | Runs a function in a transaction (a savepoint when nested) and its `lagoon.AfterCommit` callbacks after the commit. |
 | `lagoon.AfterCommit` | Registers work to run after the surrounding transaction commits. |
 | `lagoon.AfterCommitCallback` | Name of the GORM callback, `lagoon:after_commit`, that runs single-statement after-commit work. |
 | `lagoon.DSN` | Reads `database.dsn` from config. |
-| `lagoon.CheckLocale` | Fails unless the database default locale is ICU `pl-PL`. |
 | `lagoon.Migrate` | Runs framework and plugin migrations in order. |
 | `lagoon.RollbackLast` | Rolls back the last migration of one plugin. |
 | `lagoon.Status` | Lists applied migration IDs per plugin as `lagoon.StatusRow` values. |
@@ -137,7 +135,9 @@ func (p *Plugin) Migrations() []*gormigrate.Migration {
 | `lagoon.Fill` | Allow-listed mass assignment by column name. |
 | `lagoon.FillTypeError` | Returned by `lagoon.Fill` when a requested value does not fit its column; `Key` names the column. |
 | `lagoon.Validate` | Laravel-style rule validation with a `unique` database check. |
-| `lagoon.OrderBy` | Allow-listed ORDER BY. |
+| `lagoon.OrderBy` | Allow-listed ORDER BY, with an optional `lagoon.Collate`. |
+| `lagoon.Collate` | Order option that sorts the column with a named PostgreSQL collation; the name is validated and quoted. |
+| `lagoon.OrderOption` | Option type accepted by `lagoon.OrderBy`. |
 | `lagoon.Paginate` | Builds a `lagoon.Page` with `lagoon.PageMeta`. |
 | `lagoon.WithSoftDeleteCascade` | Runs a cascade inside the parent delete transaction. |
 | `lagoon.RegisterJoinTable` | Registers a custom pivot model for a many-to-many field. |
@@ -198,4 +198,4 @@ storage:
 go test ./modules/lagoon/...
 ```
 
-The database tests in `lagoon` and `lagoon/attach` start a `postgres:16-alpine` container, initialised with the ICU `pl-PL` locale, through testcontainers-go, so they need a running Docker daemon. They are skipped by `go test -short ./modules/lagoon/...`, which runs only the unit tests.
+The database tests in `lagoon` and `lagoon/attach` start a `postgres:16-alpine` container through testcontainers-go, so they need a running Docker daemon. They are skipped by `go test -short ./modules/lagoon/...`, which runs only the unit tests.
diff --git a/modules/lagoon/attach/lifecycle_test.go b/modules/lagoon/attach/lifecycle_test.go
index 0373b01..1f481aa 100644
--- a/modules/lagoon/attach/lifecycle_test.go
+++ b/modules/lagoon/attach/lifecycle_test.go
@@ -275,9 +275,6 @@ func attachGorm(t *testing.T) *gorm.DB {
 		postgres.WithUsername("attach"),
 		postgres.WithPassword("attach"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		t.Fatalf("postgres: %v", err)
diff --git a/modules/lagoon/connection.go b/modules/lagoon/connection.go
index 32f06d9..6aea6fd 100644
--- a/modules/lagoon/connection.go
+++ b/modules/lagoon/connection.go
@@ -13,13 +13,8 @@ import (
 	"gorm.io/gorm"
 )
 
-const (
-	requiredLocaleProvider = "i"
-	requiredICULocale      = "pl-PL"
-)
-
-// Open pings dsn through pgx stdlib, requires Postgres 16 ICU pl-PL, and
-// returns that exact *sql.DB plus a GORM handle opened on it.
+// Open pings dsn through pgx stdlib and returns that exact *sql.DB plus a
+// GORM handle opened on it.
 //
 // The job worker in the conga module opens its own single-connection
 // pgxpool.Pool for River LISTEN/NOTIFY. Do not create that listener pool
@@ -37,10 +32,6 @@ func Open(ctx context.Context, dsn string) (*sql.DB, *gorm.DB, error) {
 		_ = sqlDB.Close()
 		return nil, nil, fmt.Errorf("lagoon: ping postgres: %w", err)
 	}
-	if err := CheckLocale(ctx, sqlDB); err != nil {
-		_ = sqlDB.Close()
-		return nil, nil, err
-	}
 	gdb, err := gormFromSQL(sqlDB)
 	if err != nil {
 		_ = sqlDB.Close()
@@ -49,9 +40,9 @@ func Open(ctx context.Context, dsn string) (*sql.DB, *gorm.DB, error) {
 	return sqlDB, gdb, nil
 }
 
-// Use pings an existing pool, requires ICU pl-PL, and returns a GORM handle
-// opened on that exact *sql.DB. Callers that already hold a pool (tests,
-// the app boot seam) must not open a second connection.
+// Use pings an existing pool and returns a GORM handle opened on that exact
+// *sql.DB. Callers that already hold a pool (tests, the app boot seam) must
+// not open a second connection.
 func Use(ctx context.Context, sqlDB *sql.DB) (*gorm.DB, error) {
 	if sqlDB == nil {
 		return nil, fmt.Errorf("lagoon: sql db is nil")
@@ -59,9 +50,6 @@ func Use(ctx context.Context, sqlDB *sql.DB) (*gorm.DB, error) {
 	if err := sqlDB.PingContext(ctx); err != nil {
 		return nil, fmt.Errorf("lagoon: ping postgres: %w", err)
 	}
-	if err := CheckLocale(ctx, sqlDB); err != nil {
-		return nil, err
-	}
 	return gormFromSQL(sqlDB)
 }
 
@@ -127,28 +115,3 @@ func Publish(app *backpack.App, sqlDB *sql.DB, gdb *gorm.DB) error {
 	}
 	return runDatabaseHooks(app, sqlDB, gdb)
 }
-
-// CheckLocale fails unless the connected database uses ICU locale pl-PL.
-func CheckLocale(ctx context.Context, db *sql.DB) error {
-	if db == nil {
-		return fmt.Errorf("lagoon: sql db is nil")
-	}
-	var provider, icu string
-	err := db.QueryRowContext(ctx, `
-SELECT datlocprovider::text, COALESCE(daticulocale, '')
-FROM pg_database
-WHERE datname = current_database()`).Scan(&provider, &icu)
-	if err != nil {
-		return fmt.Errorf("lagoon: read database locale: %w", err)
-	}
-	return checkLocale(provider, icu)
-}
-
-func checkLocale(provider, icu string) error {
-	provider = strings.TrimSpace(provider)
-	icu = strings.TrimSpace(icu)
-	if provider == requiredLocaleProvider && icu == requiredICULocale {
-		return nil
-	}
-	return fmt.Errorf("lagoon: database locale must be ICU pl-PL (datlocprovider=%q, daticulocale=%q); got provider %q locale %q. Create the database with: CREATE DATABASE ... TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'", requiredLocaleProvider, requiredICULocale, provider, icu)
-}
diff --git a/modules/lagoon/connection_test.go b/modules/lagoon/connection_test.go
index 5114bd7..ef43e38 100644
--- a/modules/lagoon/connection_test.go
+++ b/modules/lagoon/connection_test.go
@@ -21,13 +21,6 @@ func TestUseRejectsNilSQL(t *testing.T) {
 	}
 }
 
-func TestCheckLocaleRejectsNilSQL(t *testing.T) {
-	err := CheckLocale(t.Context(), nil)
-	if err == nil || !strings.Contains(err.Error(), "sql db is nil") {
-		t.Fatalf("got %v", err)
-	}
-}
-
 func TestPublishRejectsNilHandles(t *testing.T) {
 	app := backpack.New(nil)
 	if err := Publish(nil, nil, nil); err == nil {
@@ -105,31 +98,6 @@ func TestSharedSQLPoolUsedByGORMAndClosed(t *testing.T) {
 	}
 }
 
-func TestWrongICULocaleFailsOpen(t *testing.T) {
-	admin := lagoonDB(t)
-	ctx := t.Context()
-	if _, err := admin.ExecContext(ctx, `CREATE DATABASE lagoon_locale_fail TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER libc LOCALE 'C'`); err != nil && !strings.Contains(err.Error(), "already exists") {
-		t.Fatalf("create libc database: %v", err)
-	}
-	t.Cleanup(func() {
-		_, _ = admin.ExecContext(ctx, `DROP DATABASE IF EXISTS lagoon_locale_fail WITH (FORCE)`)
-	})
-	failDSN, err := dsnWithDB(lagoonDSN, "lagoon_locale_fail")
-	if err != nil {
-		t.Fatal(err)
-	}
-	_, _, err = Open(ctx, failDSN)
-	if err == nil {
-		t.Fatal("wrong locale must fail boot")
-	}
-	msg := err.Error()
-	for _, want := range []string{"ICU", "pl-PL", "CREATE DATABASE", "LOCALE_PROVIDER icu"} {
-		if !strings.Contains(msg, want) {
-			t.Fatalf("missing %q in %s", want, msg)
-		}
-	}
-}
-
 func TestOpenFromAppReadsDSN(t *testing.T) {
 	_, dsn := dedicatedDB(t, "lagoon_from_app")
 	dir := t.TempDir()
diff --git a/modules/lagoon/example_test.go b/modules/lagoon/example_test.go
index 4d69de0..2e0573b 100644
--- a/modules/lagoon/example_test.go
+++ b/modules/lagoon/example_test.go
@@ -208,6 +208,27 @@ func ExampleOrderBy() {
 	// lagoon: order direction "asc; DROP TABLE acme_blog_posts" is not allow-listed
 }
 
+func ExampleCollate() {
+	// A dry-run handle shows the SQL without a database.
+	db, _ := gorm.Open(postgres.New(postgres.Config{DSN: "host=127.0.0.1"}), &gorm.Config{DryRun: true, DisableAutomaticPing: true})
+	allowed := []string{"title", "views"}
+
+	// Polish alphabetical order, whatever the database's default locale.
+	q, err := lagoon.OrderBy(db.Model(&Post{}), "title", "asc", allowed, lagoon.Collate("pl-x-icu"))
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	var posts []Post
+	fmt.Println(q.Find(&posts).Statement.SQL.String())
+
+	_, err = lagoon.OrderBy(db, "title", "asc", allowed, lagoon.Collate(`pl-x-icu" ASC, (SELECT 1) --`))
+	fmt.Println(err)
+	// Output:
+	// SELECT * FROM "acme_blog_posts" WHERE "acme_blog_posts"."deleted_at" IS NULL ORDER BY title COLLATE "pl-x-icu" ASC
+	// lagoon: order collation "pl-x-icu\" ASC, (SELECT 1) --" is not a valid collation name
+}
+
 func ExamplePaginate() {
 	rows := []map[string]any{{"id": 3, "title": "Third"}}
 	page := lagoon.Paginate(rows, 2, 2, 3)
diff --git a/modules/lagoon/export_docs_test.go b/modules/lagoon/export_docs_test.go
index 0fbc45b..e098cdb 100644
--- a/modules/lagoon/export_docs_test.go
+++ b/modules/lagoon/export_docs_test.go
@@ -6,8 +6,8 @@ import (
 	"gorm.io/gorm"
 )
 
-// DocsDB returns a GORM handle on a fresh ICU pl-PL database named name in
-// this package's Postgres harness, for the database-backed docs examples in
+// DocsDB returns a GORM handle on a fresh database named name in this
+// package's Postgres harness, for the database-backed docs examples in
 // example_test.go. It skips under -short and fails when the harness has no
 // database, like the package's other database tests.
 func DocsDB(t *testing.T, name string) *gorm.DB {
diff --git a/modules/lagoon/migrations_test.go b/modules/lagoon/migrations_test.go
index e5c127f..565b9ca 100644
--- a/modules/lagoon/migrations_test.go
+++ b/modules/lagoon/migrations_test.go
@@ -39,22 +39,6 @@ func TestHistoryTableName(t *testing.T) {
 	}
 }
 
-func TestCheckLocaleMessage(t *testing.T) {
-	if err := checkLocale("i", "pl-PL"); err != nil {
-		t.Fatal(err)
-	}
-	err := checkLocale("c", "en_US")
-	if err == nil {
-		t.Fatal("want locale error")
-	}
-	msg := err.Error()
-	for _, want := range []string{"ICU", "pl-PL", "CREATE DATABASE", "LOCALE_PROVIDER icu", "en_US"} {
-		if !strings.Contains(msg, want) {
-			t.Fatalf("missing %q in %s", want, msg)
-		}
-	}
-}
-
 func TestRuntimeCommandsRegisterBareAndColonNames(t *testing.T) {
 	cmds := RuntimeCommands(nil, nil)
 	names := map[string]bool{}
diff --git a/modules/lagoon/order.go b/modules/lagoon/order.go
index 231b7d5..69bd00a 100644
--- a/modules/lagoon/order.go
+++ b/modules/lagoon/order.go
@@ -7,33 +7,100 @@ import (
 	"gorm.io/gorm"
 )
 
-// OrderBy appends a database-default ORDER BY for an allow-listed qualified
-// column. Identifiers and directions are never taken from untrusted input:
-// column must match allowed exactly, and dir must be asc or desc. No COLLATE
-// is emitted; Postgres ICU pl-PL is the database default (CheckLocale).
-func OrderBy(db *gorm.DB, column, dir string, allowed []string) (*gorm.DB, error) {
+// maxCollationName is PostgreSQL's identifier limit (NAMEDATALEN-1).
+const maxCollationName = 63
+
+// OrderOption changes how OrderBy builds its ORDER BY clause.
+type OrderOption func(*orderOptions)
+
+type orderOptions struct {
+	collation    string
+	hasCollation bool
+}
+
+// Collate sorts the column with the named PostgreSQL collation, for example
+// the ICU collation pl-x-icu for Polish alphabetical order. ICU collations
+// exist in any ICU-enabled PostgreSQL server, so they need no database
+// setup. The name is validated and emitted as a double-quoted identifier;
+// an invalid name makes OrderBy return an error.
+func Collate(name string) OrderOption {
+	return func(o *orderOptions) {
+		o.collation = name
+		o.hasCollation = true
+	}
+}
+
+// OrderBy appends an ORDER BY for an allow-listed qualified column.
+// Identifiers and directions are never taken from untrusted input: column
+// must match allowed exactly, and dir must be asc or desc. No COLLATE is
+// emitted unless Collate is passed; without it, text sorts by the
+// database's default collation.
+func OrderBy(db *gorm.DB, column, dir string, allowed []string, opts ...OrderOption) (*gorm.DB, error) {
 	if db == nil {
 		return nil, fmt.Errorf("lagoon: gorm db is nil")
 	}
-	clause, err := orderClause(column, dir, allowed)
+	clause, err := orderClause(column, dir, allowed, resolveOrderOptions(opts))
 	if err != nil {
 		return nil, err
 	}
 	return db.Order(clause), nil
 }
 
-func orderClause(column, dir string, allowed []string) (string, error) {
+func resolveOrderOptions(opts []OrderOption) orderOptions {
+	var o orderOptions
+	for _, opt := range opts {
+		if opt != nil {
+			opt(&o)
+		}
+	}
+	return o
+}
+
+func orderClause(column, dir string, allowed []string, opts orderOptions) (string, error) {
 	if !allowListed(column, allowed) {
 		return "", fmt.Errorf("lagoon: order column %q is not allow-listed", column)
 	}
+	var direction string
 	switch strings.ToLower(strings.TrimSpace(dir)) {
 	case "asc":
-		return column + " ASC", nil
+		direction = "ASC"
 	case "desc":
-		return column + " DESC", nil
+		direction = "DESC"
 	default:
 		return "", fmt.Errorf("lagoon: order direction %q is not allow-listed", dir)
 	}
+	if !opts.hasCollation {
+		return column + " " + direction, nil
+	}
+	if !validCollationName(opts.collation) {
+		return "", fmt.Errorf("lagoon: order collation %q is not a valid collation name", opts.collation)
+	}
+	return column + " COLLATE " + quoteCollation(opts.collation) + " " + direction, nil
+}
+
+// validCollationName accepts 1-63 ASCII bytes: letters, digits and
+// underscore first, then letters, digits, '_', '-', '.' and '@'. The set
+// excludes the double quote, so a valid name cannot leave its identifier.
+func validCollationName(name string) bool {
+	if len(name) == 0 || len(name) > maxCollationName {
+		return false
+	}
+	for i := 0; i < len(name); i++ {
+		c := name[i]
+		switch {
+		case c >= 'a' && c <= 'z', c >= 'A' && c <= 'Z', c >= '0' && c <= '9', c == '_':
+		case i > 0 && (c == '-' || c == '.' || c == '@'):
+		default:
+			return false
+		}
+	}
+	return true
+}
+
+// quoteCollation wraps a validated collation name as a PostgreSQL quoted
+// identifier.
+func quoteCollation(name string) string {
+	return `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
 }
 
 func allowListed(column string, allowed []string) bool {
diff --git a/modules/lagoon/order_test.go b/modules/lagoon/order_test.go
index 152a202..3a93832 100644
--- a/modules/lagoon/order_test.go
+++ b/modules/lagoon/order_test.go
@@ -1,42 +1,219 @@
 package lagoon
 
 import (
+	"context"
+	"fmt"
+	"reflect"
 	"strings"
 	"testing"
+
+	"gorm.io/gorm"
 )
 
 func TestOrderClauseAllowList(t *testing.T) {
-	allowed := []string{"golem15_fonoteka_genres.name", "items.title"}
+	allowed := []string{"acme_blog_posts.title", "items.title"}
 
-	got, err := orderClause("golem15_fonoteka_genres.name", "asc", allowed)
+	got, err := orderClause("acme_blog_posts.title", "asc", allowed, orderOptions{})
 	if err != nil {
 		t.Fatal(err)
 	}
-	if got != "golem15_fonoteka_genres.name ASC" {
+	if got != "acme_blog_posts.title ASC" {
 		t.Fatalf("got %q", got)
 	}
 	if strings.Contains(strings.ToLower(got), "collate") {
 		t.Fatalf("must not emit COLLATE: %q", got)
 	}
 
-	got, err = orderClause("items.title", "DESC", allowed)
+	got, err = orderClause("items.title", "DESC", allowed, orderOptions{})
 	if err != nil {
 		t.Fatal(err)
 	}
 	if got != "items.title DESC" {
 		t.Fatalf("got %q", got)
 	}
+	if strings.Contains(strings.ToLower(got), "collate") {
+		t.Fatalf("must not emit COLLATE: %q", got)
+	}
 
-	if _, err := orderClause("golem15_fonoteka_genres.name;drop table x", "asc", allowed); err == nil {
+	if _, err := orderClause("acme_blog_posts.title;drop table x", "asc", allowed, orderOptions{}); err == nil {
 		t.Fatal("want reject unknown column")
 	}
-	if _, err := orderClause("golem15_fonoteka_genres.name", "ascending", allowed); err == nil {
+	if _, err := orderClause("acme_blog_posts.title", "ascending", allowed, orderOptions{}); err == nil {
 		t.Fatal("want reject unknown direction")
 	}
 	if _, err := OrderBy(nil, "items.title", "asc", allowed); err == nil {
 		t.Fatal("want nil db error")
 	}
-	if _, err := orderClause("items.title", "asc", nil); err == nil {
+	if _, err := orderClause("items.title", "asc", nil, orderOptions{}); err == nil {
 		t.Fatal("empty allow-list must reject")
 	}
 }
+
+func TestOrderClauseCollation(t *testing.T) {
+	allowed := []string{"items.title"}
+	opts := resolveOrderOptions([]OrderOption{Collate("pl-x-icu")})
+
+	got, err := orderClause("items.title", "asc", allowed, opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != `items.title COLLATE "pl-x-icu" ASC` {
+		t.Fatalf("got %q", got)
+	}
+	got, err = orderClause("items.title", "DESC", allowed, opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != `items.title COLLATE "pl-x-icu" DESC` {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestCollateAcceptsValidNames(t *testing.T) {
+	allowed := []string{"items.title"}
+	for _, name := range []string{
+		"pl-x-icu",
+		"und-x-icu",
+		"en-US-x-icu",
+		"C",
+		"POSIX",
+		"ucs_basic",
+		"default",
+		"sr_RS.utf8@latin",
+		strings.Repeat("a", 63),
+	} {
+		got, err := orderClause("items.title", "asc", allowed, resolveOrderOptions([]OrderOption{Collate(name)}))
+		if err != nil {
+			t.Fatalf("%q: %v", name, err)
+		}
+		want := `items.title COLLATE "` + name + `" ASC`
+		if got != want {
+			t.Fatalf("%q: got %q want %q", name, got, want)
+		}
+	}
+}
+
+func TestCollateRejectsInvalidNames(t *testing.T) {
+	allowed := []string{"items.title"}
+	db := &gorm.DB{}
+	for _, name := range []string{
+		"",
+		strings.Repeat("a", 64),
+		"pl x icu",
+		`pl-x-icu"`,
+		`pl-x-icu" ASC, (SELECT 1) --`,
+		"pl;DROP TABLE x",
+		`pl\x-icu`,
+		"pl\x00x-icu",
+		"pł-x-icu",
+		"-pl-x-icu",
+		".pl-x-icu",
+	} {
+		want := fmt.Sprintf("lagoon: order collation %q is not a valid collation name", name)
+		_, err := orderClause("items.title", "asc", allowed, resolveOrderOptions([]OrderOption{Collate(name)}))
+		if err == nil || err.Error() != want {
+			t.Fatalf("%q: got %v want %s", name, err, want)
+		}
+		q, err := OrderBy(db, "items.title", "asc", allowed, Collate(name))
+		if q != nil || err == nil || err.Error() != want {
+			t.Fatalf("OrderBy %q: got (%v, %v)", name, q, err)
+		}
+	}
+	if db.Statement != nil {
+		t.Fatal("rejected collation must not touch the GORM handle")
+	}
+}
+
+func TestCollateOptionOrdering(t *testing.T) {
+	allowed := []string{"items.title"}
+
+	got, err := orderClause("items.title", "asc", allowed, resolveOrderOptions([]OrderOption{Collate("C"), Collate("pl-x-icu")}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != `items.title COLLATE "pl-x-icu" ASC` {
+		t.Fatalf("last Collate must win: %q", got)
+	}
+
+	got, err = orderClause("items.title", "asc", allowed, resolveOrderOptions(nil))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "items.title ASC" {
+		t.Fatalf("no options must keep the plain clause: %q", got)
+	}
+
+	// Column and direction are checked before the collation.
+	bad := resolveOrderOptions([]OrderOption{Collate(`bad"name`)})
+	_, err = orderClause("items.other", "asc", allowed, bad)
+	if err == nil || !strings.Contains(err.Error(), "order column") {
+		t.Fatalf("column check must run first: %v", err)
+	}
+	_, err = orderClause("items.title", "sideways", allowed, bad)
+	if err == nil || !strings.Contains(err.Error(), "order direction") {
+		t.Fatalf("direction check must run second: %v", err)
+	}
+}
+
+func TestCollatePolishOrderOnLibcDatabase(t *testing.T) {
+	admin := lagoonDB(t)
+	ctx := t.Context()
+	const name = "lagoon_collate_libc"
+	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER libc LOCALE 'C'`); err != nil && !strings.Contains(err.Error(), "already exists") {
+		t.Fatalf("create libc database: %v", err)
+	}
+	dsn, err := dsnWithDB(lagoonDSN, name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB, gdb, err := Open(ctx, dsn)
+	if err != nil {
+		t.Fatalf("Open must accept a libc 'C' database: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = sqlDB.Close()
+		_, _ = admin.ExecContext(context.Background(), `DROP DATABASE IF EXISTS `+name+` WITH (FORCE)`)
+	})
+	if _, err := Use(ctx, sqlDB); err != nil {
+		t.Fatalf("Use must accept a libc 'C' database: %v", err)
+	}
+	if _, err := sqlDB.ExecContext(ctx, `CREATE TABLE words (name text)`); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := sqlDB.ExecContext(ctx, `INSERT INTO words (name) VALUES ('Zebra'), ('Łoś'), ('Lis'), ('Mysz')`); err != nil {
+		t.Fatal(err)
+	}
+	allowed := []string{"words.name"}
+	scan := func(opts ...OrderOption) ([]string, error) {
+		q, err := OrderBy(gdb.Table("words"), "words.name", "asc", allowed, opts...)
+		if err != nil {
+			return nil, err
+		}
+		var names []string
+		if err := q.Pluck("name", &names).Error; err != nil {
+			return nil, err
+		}
+		return names, nil
+	}
+
+	plain, err := scan()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := []string{"Lis", "Mysz", "Zebra", "Łoś"}; !reflect.DeepEqual(plain, want) {
+		t.Fatalf("plain order on libc 'C': got %v want %v", plain, want)
+	}
+
+	polish, err := scan(Collate("pl-x-icu"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := []string{"Lis", "Łoś", "Mysz", "Zebra"}; !reflect.DeepEqual(polish, want) {
+		t.Fatalf("pl-x-icu order: got %v want %v", polish, want)
+	}
+
+	_, err = scan(Collate("no-such-collation-x"))
+	if err == nil || !strings.Contains(err.Error(), "no-such-collation-x") {
+		t.Fatalf("unknown collation must reach Postgres as an identifier: %v", err)
+	}
+}
diff --git a/modules/lagoon/postgres_test.go b/modules/lagoon/postgres_test.go
index 2cfbd3e..eec84a4 100644
--- a/modules/lagoon/postgres_test.go
+++ b/modules/lagoon/postgres_test.go
@@ -55,9 +55,6 @@ func startLagoonPostgres(ctx context.Context) error {
 		postgres.WithUsername("lagoon"),
 		postgres.WithPassword("lagoon"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		return err
@@ -108,7 +105,7 @@ func dedicatedDB(t *testing.T, name string) (*sql.DB, string) {
 	admin := lagoonDB(t)
 	ctx := t.Context()
 	quoted := `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
-	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+quoted+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`); err != nil && !strings.Contains(err.Error(), "already exists") {
+	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+quoted+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil && !strings.Contains(err.Error(), "already exists") {
 		t.Fatalf("create %s: %v", name, err)
 	}
 	dsn, err := dsnWithDB(lagoonDSN, name)
diff --git a/modules/lighthouse/postgres_test.go b/modules/lighthouse/postgres_test.go
index 570959f..e8c0acd 100644
--- a/modules/lighthouse/postgres_test.go
+++ b/modules/lighthouse/postgres_test.go
@@ -58,9 +58,6 @@ func startLighthousePostgres(ctx context.Context) error {
 		postgres.WithUsername("lighthouse"),
 		postgres.WithPassword("lighthouse"),
 		postgres.BasicWaitStrategies(),
-		testcontainers.WithEnv(map[string]string{
-			"POSTGRES_INITDB_ARGS": "--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8",
-		}),
 	)
 	if err != nil {
 		return err
@@ -106,14 +103,14 @@ func adminDB(t *testing.T) *sql.DB {
 	return lhSQL
 }
 
-// migratedDB returns a dedicated ICU pl-PL database migrated with
+// migratedDB returns a dedicated database migrated with
 // lagoon.Migrate (River v7 and summer_jobs) plus its DSN.
 func migratedDB(t *testing.T) (*sql.DB, string) {
 	t.Helper()
 	admin := adminDB(t)
 	ctx := t.Context()
 	name := fmt.Sprintf("lighthouse_%d", dbSeq.Add(1))
-	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8' LOCALE_PROVIDER icu ICU_LOCALE 'pl-PL'`); err != nil && !strings.Contains(err.Error(), "already exists") {
+	if _, err := admin.ExecContext(ctx, `CREATE DATABASE `+name+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil && !strings.Contains(err.Error(), "already exists") {
 		t.Fatalf("create %s: %v", name, err)
 	}
 	dsn, err := dsnWithDB(lhDSN, name)
diff --git a/scripts/check-phase8.sh b/scripts/check-phase8.sh
index 302cd7a..1082b28 100755
--- a/scripts/check-phase8.sh
+++ b/scripts/check-phase8.sh
@@ -249,10 +249,8 @@ stage_postgres() {
 	local dir
 	dir="$(phase8_workdir)"
 	PHASE8_PG_CONTAINER="phase8-pg-$$"
-	# ICU pl-PL locale matches every other Go test's testcontainers Postgres
-	# in this project (e.g. plugins/golem15/fonoteka/updates's own
-	# startOAuthUpdatesPostgres): lagoon.Use refuses any other locale
-	# provider/locale at boot.
+	# The ICU pl-PL locale matches the application's recommended database;
+	# lagoon itself no longer checks the database locale.
 	docker run -d --rm --name "$PHASE8_PG_CONTAINER" \
 		-e POSTGRES_PASSWORD=phase8 -e POSTGRES_DB=fonoteka_phase8 \
 		-e POSTGRES_INITDB_ARGS="--locale-provider=icu --icu-locale=pl-PL --encoding=UTF8" \