diff --git a/src/corelib/global/qxpfunctional.h b/src/corelib/global/qxpfunctional.h
index cc2942b1c6a..cbeef8b2932 100644
--- a/src/corelib/global/qxpfunctional.h
+++ b/src/corelib/global/qxpfunctional.h
@@ -141,9 +141,11 @@ public:
 protected:
     template <
         class T,
-        std::enable_if_t<std::conjunction_v<
-            std::negation<std::is_same<q20::remove_cvref_t<T>, function_ref_base>>,
-            std::negation<std::is_pointer<T>>
+        std::enable_if_t<std::negation_v<
+            std::disjunction<
+                std::is_same<T, function_ref_base>,
+                std::is_pointer<T>
+            >
         >, bool> = true
     >
     function_ref_base& operator=(T) = delete;