diff --git a/app/flatpak-builtins-config.c b/app/flatpak-builtins-config.c
index d5b72a9f..8b4855fd 100644
--- a/app/flatpak-builtins-config.c
+++ b/app/flatpak-builtins-config.c
@@ -199,18 +199,6 @@ get_lang_default (FlatpakDir *dir)
   return g_strjoinv (";", langs);
 }
 
-static char *
-parse_string (const char *value, GError **error)
-{
-  return g_strdup (value);
-}
-
-static char *
-print_string (const char *value)
-{
-  return g_strdup (value);
-}
-
 typedef struct
 {
   const char *name;
@@ -222,7 +210,6 @@ typedef struct
 ConfigKey keys[] = {
   { "languages", parse_lang, print_lang, get_lang_default },
   { "extra-languages", parse_locale, print_locale, NULL },
-  { "sideload-repos", parse_string, print_string, NULL },
 };
 
 static ConfigKey *
diff --git a/system-helper/flatpak-system-helper.c b/system-helper/flatpak-system-helper.c
index 6c06e5a6..0f0b7a33 100644
--- a/system-helper/flatpak-system-helper.c
+++ b/system-helper/flatpak-system-helper.c
@@ -1138,9 +1138,7 @@ handle_configure (FlatpakSystemHelper   *object,
       return TRUE;
     }
 
-  if ((strcmp (arg_key, "languages") != 0) &&
-      (strcmp (arg_key, "extra-languages") != 0) &&
-      (strcmp (arg_key, "sideload-repos") != 0))
+  if ((strcmp (arg_key, "languages") != 0) && (strcmp (arg_key, "extra-languages") != 0))
     {
       g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
                                              "Unsupported key: %s", arg_key);