diff --git a/pkgs/development/lua-modules/lib.nix b/pkgs/development/lua-modules/lib.nix
index 7c7ffcccf263..a07b23ff9cd2 100644
--- a/pkgs/development/lua-modules/lib.nix
+++ b/pkgs/development/lua-modules/lib.nix
@@ -82,11 +82,11 @@ rec {
   };
   */
   generateLuarocksConfig = {
-      externalDeps
+    externalDeps ? []
     # a list of lua derivations
-    , requiredLuaRocks
+    , requiredLuaRocks ? []
     , extraVariables ? {}
-    , rocksSubdir
+    , rocksSubdir ? "rocks-subdir"
     }: let
       rocksTrees = lib.imap0
         (i: dep: {