diff --git a/pkgs/lib/options.nix b/pkgs/lib/options.nix
index f42eced37d7..683b2d05dfc 100644
--- a/pkgs/lib/options.nix
+++ b/pkgs/lib/options.nix
@@ -295,7 +295,7 @@ rec {
   # `onDelay' and `onGlobalDelay'.
   delayProperties = attrs:
     let cleanAttrs = rmProperties attrs; in
-    if cleanAttrs != attrs then
+    if isProperty attrs then
       lib.mapAttrs (a: v:
         lib.addErrorContext "while moving properties on the attribute `${a}'." (
           triggerPropertiesGlobalDelay a (