diff --git a/src/corelib/kernel/qcoreapplication.h b/src/corelib/kernel/qcoreapplication.h
index 2514c7630b..ae01cdee9a 100644
--- a/src/corelib/kernel/qcoreapplication.h
+++ b/src/corelib/kernel/qcoreapplication.h
@@ -126,6 +126,7 @@ public:
                            Functor &&func)
     {
         using Prototype = void(*)(QPermission);
+        QtPrivate::AssertCompatibleFunctions<Prototype, Functor>();
         requestPermission(permission,
                           QtPrivate::makeSlotObject<Prototype>(std::forward<Functor>(func)),
                           receiver);
diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index e8b9b4a209..721193fe91 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -512,6 +512,21 @@ namespace QtPrivate {
                                                      ActualArguments, void>(std::forward<Functor>(func));
         }
     }
+
+    template<typename Prototype, typename Functor, typename = void>
+    struct AreFunctionsCompatible : std::false_type {};
+    template<typename Prototype, typename Functor>
+    struct AreFunctionsCompatible<Prototype, Functor, std::enable_if_t<
+        std::is_same_v<decltype(QtPrivate::makeSlotObject<Prototype>(std::forward<Functor>(std::declval<Functor>()))),
+        QtPrivate::QSlotObjectBase *>>
+    > : std::true_type {};
+
+    template<typename Prototype, typename Functor>
+    inline constexpr bool AssertCompatibleFunctions() {
+        static_assert(AreFunctionsCompatible<Prototype, Functor>::value,
+                      "Functor is not compatible with expected prototype!");
+        return true;
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/src/network/kernel/qhostinfo.h b/src/network/kernel/qhostinfo.h
index 9b420bd3ca..1f18bf8302 100644
--- a/src/network/kernel/qhostinfo.h
+++ b/src/network/kernel/qhostinfo.h
@@ -66,6 +66,7 @@ public:
                                  Functor &&func)
     {
         using Prototype = void(*)(QHostInfo);
+        QtPrivate::AssertCompatibleFunctions<Prototype, Functor>();
         return lookupHostImpl(name, receiver,
                               QtPrivate::makeSlotObject<Prototype>(std::forward<Functor>(func)),
                               nullptr);
diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 649f075a02..76ceb84271 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -8377,6 +8377,7 @@ public:
     template<typename Functor>
     bool callMe0(const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *, Functor &&func)
     {
+        QtPrivate::AssertCompatibleFunctions<Prototype0, Functor>();
         auto *slotObject = QtPrivate::makeSlotObject<Prototype0>(std::forward<Functor>(func));
         slotObject->destroyIfLastRef();
         return true;
@@ -8391,6 +8392,7 @@ public:
     template<typename Functor>
     bool callMe1(const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *, Functor &&func)
     {
+        QtPrivate::AssertCompatibleFunctions<Prototype1, Functor>();
         auto *slotObject = QtPrivate::makeSlotObject<Prototype1>(std::forward<Functor>(func));
         slotObject->destroyIfLastRef();
         return true;
@@ -8406,14 +8408,6 @@ public:
 static void freeFunction0() {}
 static void freeFunction1(QString) {}
 
-template<typename Prototype, typename Functor, typename = void>
-struct AreFunctionsCompatible : std::false_type {};
-template<typename Prototype, typename Functor>
-struct AreFunctionsCompatible<Prototype, Functor, std::enable_if_t<
-    std::is_same_v<decltype(QtPrivate::makeSlotObject<Prototype>(std::forward<Functor>(std::declval<Functor>()))),
-    QtPrivate::QSlotObjectBase *>>
-> : std::true_type {};
-
 template<typename Prototype, typename Functor>
 inline constexpr bool compiles(Functor &&) {
     return QtPrivate::AreFunctionsCompatible<Prototype, Functor>::value;