diff --git a/private/playlists.rkt b/private/playlists.rkt
index 8872aa4..c0c4e95 100644
--- a/private/playlists.rkt
+++ b/private/playlists.rkt
@@ -219,7 +219,7 @@
       (save-user-language! store "hans" "fi")
       (check-equal? (load-user-language store "hans") "fi")
       (check-exn exn:fail:contract?
-                 (λ () (save-user-language! store "hans" "it")))
+                 (λ () (save-user-language! store "hans" "da")))
 
       ;; Rewriting the user's GUID index durably removes the omitted playlist.
       (save-user-playlists!
diff --git a/private/translate.rkt b/private/translate.rkt
index 676a14c..c31cfd1 100644
--- a/private/translate.rkt
+++ b/private/translate.rkt
@@ -1,6 +1,7 @@
 #lang racket/base
 
-(require racket/string)
+(require racket/list
+         racket/string)
 
 (provide tr
          __
@@ -338,9 +339,18 @@
   (require rackunit)
 
   (define original-language (current-lang))
+  (define english-keys
+    (sort (hash-keys (hash-ref translation-map 'en)) symbol<?))
   (dynamic-wind
     void
     (λ ()
+      (for ((entry (in-list (languages))))
+        (define candidate (car entry))
+        (check-equal?
+         (sort (hash-keys (hash-ref translation-map candidate)) symbol<?)
+         english-keys)
+        (set-lang! candidate)
+        (check-true (string? (tr 'connected))))
       (set-lang! 'nl)
       (check-equal? (tr 'connected) "Verbonden")
       (set-lang! 'de)