diff --git a/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp b/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
index b3cc81d928a..fe89e713de1 100644
--- a/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
@@ -17,7 +17,7 @@ namespace JS {
 
 // 10.3.3 CreateBuiltinFunction ( behaviour, length, name, additionalInternalSlotsList [ , realm [ , prototype [ , prefix ] ] ] ), https://tc39.es/ecma262/#sec-createbuiltinfunction
 // NOTE: This doesn't consider additionalInternalSlotsList, which is rarely used, and can either be implemented using only the `function` lambda, or needs a NativeFunction subclass.
-NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, SafeFunction<ThrowCompletionOr<Value>(VM&)> behaviour, i32 length, PropertyKey const& name, Optional<Realm*> realm, Optional<Object*> prototype, Optional<StringView> const& prefix)
+NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Function<ThrowCompletionOr<Value>(VM&)> behaviour, i32 length, PropertyKey const& name, Optional<Realm*> realm, Optional<Object*> prototype, Optional<StringView> const& prefix)
 {
     auto& vm = allocating_realm.vm();
 
@@ -37,7 +37,7 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
     // 7. Set func.[[Extensible]] to true.
     // 8. Set func.[[Realm]] to realm.
     // 9. Set func.[[InitialName]] to null.
-    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, move(behaviour), prototype.value(), *realm.value());
+    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, JS::create_heap_function(vm.heap(), move(behaviour)), prototype.value(), *realm.value());
 
     // 10. Perform SetFunctionLength(func, length).
     function->set_function_length(length);
@@ -52,12 +52,12 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
     return function;
 }
 
-NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& realm, DeprecatedFlyString const& name, SafeFunction<ThrowCompletionOr<Value>(VM&)> function)
+NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& realm, DeprecatedFlyString const& name, Function<ThrowCompletionOr<Value>(VM&)> function)
 {
-    return realm.heap().allocate<NativeFunction>(realm, name, move(function), realm.intrinsics().function_prototype());
+    return realm.heap().allocate<NativeFunction>(realm, name, JS::create_heap_function(realm.heap(), move(function)), realm.intrinsics().function_prototype());
 }
 
-NativeFunction::NativeFunction(SafeFunction<ThrowCompletionOr<Value>(VM&)> native_function, Object* prototype, Realm& realm)
+NativeFunction::NativeFunction(JS::GCPtr<JS::HeapFunction<ThrowCompletionOr<Value>(VM&)>> native_function, Object* prototype, Realm& realm)
     : FunctionObject(realm, prototype)
     , m_native_function(move(native_function))
     , m_realm(&realm)
@@ -74,7 +74,7 @@ NativeFunction::NativeFunction(Object& prototype)
 {
 }
 
-NativeFunction::NativeFunction(DeprecatedFlyString name, SafeFunction<ThrowCompletionOr<Value>(VM&)> native_function, Object& prototype)
+NativeFunction::NativeFunction(DeprecatedFlyString name, JS::GCPtr<JS::HeapFunction<ThrowCompletionOr<Value>(VM&)>> native_function, Object& prototype)
     : FunctionObject(prototype)
     , m_name(move(name))
     , m_native_function(move(native_function))
@@ -219,7 +219,8 @@ ThrowCompletionOr<NonnullGCPtr<Object>> NativeFunction::internal_construct(Marke
 
 ThrowCompletionOr<Value> NativeFunction::call()
 {
-    return m_native_function(vm());
+    VERIFY(m_native_function);
+    return m_native_function->function()(vm());
 }
 
 ThrowCompletionOr<NonnullGCPtr<Object>> NativeFunction::construct(FunctionObject&)
diff --git a/Userland/Libraries/LibJS/Runtime/NativeFunction.h b/Userland/Libraries/LibJS/Runtime/NativeFunction.h
index d4eb48596fb..a402a63857c 100644
--- a/Userland/Libraries/LibJS/Runtime/NativeFunction.h
+++ b/Userland/Libraries/LibJS/Runtime/NativeFunction.h
@@ -9,10 +9,10 @@
 
 #include <AK/Badge.h>
 #include <AK/Optional.h>
+#include <LibJS/Heap/HeapFunction.h>
 #include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibJS/Runtime/PropertyKey.h>
-#include <LibJS/SafeFunction.h>
 
 namespace JS {
 
@@ -20,8 +20,8 @@ class NativeFunction : public FunctionObject {
     JS_OBJECT(NativeFunction, FunctionObject);
 
 public:
-    static NonnullGCPtr<NativeFunction> create(Realm&, SafeFunction<ThrowCompletionOr<Value>(VM&)> behaviour, i32 length, PropertyKey const& name, Optional<Realm*> = {}, Optional<Object*> prototype = {}, Optional<StringView> const& prefix = {});
-    static NonnullGCPtr<NativeFunction> create(Realm&, DeprecatedFlyString const& name, SafeFunction<ThrowCompletionOr<Value>(VM&)>);
+    static NonnullGCPtr<NativeFunction> create(Realm&, Function<ThrowCompletionOr<Value>(VM&)> behaviour, i32 length, PropertyKey const& name, Optional<Realm*> = {}, Optional<Object*> prototype = {}, Optional<StringView> const& prefix = {});
+    static NonnullGCPtr<NativeFunction> create(Realm&, DeprecatedFlyString const& name, Function<ThrowCompletionOr<Value>(VM&)>);
 
     virtual ~NativeFunction() override = default;
 
@@ -43,16 +43,22 @@ public:
 
 protected:
     NativeFunction(DeprecatedFlyString name, Object& prototype);
-    NativeFunction(SafeFunction<ThrowCompletionOr<Value>(VM&)>, Object* prototype, Realm& realm);
-    NativeFunction(DeprecatedFlyString name, SafeFunction<ThrowCompletionOr<Value>(VM&)>, Object& prototype);
+    NativeFunction(JS::GCPtr<JS::HeapFunction<ThrowCompletionOr<Value>(VM&)>>, Object* prototype, Realm& realm);
+    NativeFunction(DeprecatedFlyString name, JS::GCPtr<JS::HeapFunction<ThrowCompletionOr<Value>(VM&)>>, Object& prototype);
     explicit NativeFunction(Object& prototype);
 
+    virtual void visit_edges(Cell::Visitor& visitor) override
+    {
+        Base::visit_edges(visitor);
+        visitor.visit(m_native_function);
+    }
+
 private:
     virtual bool is_native_function() const final { return true; }
 
     DeprecatedFlyString m_name;
     Optional<DeprecatedFlyString> m_initial_name; // [[InitialName]]
-    SafeFunction<ThrowCompletionOr<Value>(VM&)> m_native_function;
+    JS::GCPtr<JS::HeapFunction<ThrowCompletionOr<Value>(VM&)>> m_native_function;
     GCPtr<Realm> m_realm;
 };