diff --git a/tide/proxy.go b/tide/proxy.go
index 19bac45..688696b 100644
--- a/tide/proxy.go
+++ b/tide/proxy.go
@@ -107,7 +107,7 @@ func NewProxy(cfg ProxyConfig) (*Proxy, error) {
 		},
 		ModifyResponse: p.modifyResponse,
 		ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
-			http.Error(w, "tide: upstream error", http.StatusBadGateway)
+			http.Error(w, "tide: upstream error: "+err.Error(), http.StatusBadGateway)
 		},
 	}
 	return p, nil