diff --git a/dlls/ext-ms-win-ntuser-windowclass-l1-1-0/ext-ms-win-ntuser-windowclass-l1-1-0.spec b/dlls/ext-ms-win-ntuser-windowclass-l1-1-0/ext-ms-win-ntuser-windowclass-l1-1-0.spec
index 8b2ab2b2603..ad8dafe9f7d 100644
--- a/dlls/ext-ms-win-ntuser-windowclass-l1-1-0/ext-ms-win-ntuser-windowclass-l1-1-0.spec
+++ b/dlls/ext-ms-win-ntuser-windowclass-l1-1-0/ext-ms-win-ntuser-windowclass-l1-1-0.spec
@@ -5,11 +5,13 @@
 @ stdcall GetClassNameA(long ptr long) user32.GetClassNameA
 @ stdcall GetClassNameW(long ptr long) user32.GetClassNameW
 @ stdcall GetWindowLongA(long long) user32.GetWindowLongA
+@ stdcall -arch=win64 GetWindowLongPtrW(long long) user32.GetWindowLongPtrW
 @ stdcall GetWindowLongW(long long) user32.GetWindowLongW
 @ stdcall RegisterClassA(ptr) user32.RegisterClassA
 @ stdcall RegisterClassExW(ptr) user32.RegisterClassExW
 @ stdcall RegisterClassW(ptr) user32.RegisterClassW
 @ stdcall SetWindowLongA(long long long) user32.SetWindowLongA
+@ stdcall -arch=win64 SetWindowLongPtrW(long long long) user32.SetWindowLongPtrW
 @ stdcall SetWindowLongW(long long long) user32.SetWindowLongW
 @ stdcall UnregisterClassA(str long) user32.UnregisterClassA
 @ stdcall UnregisterClassW(wstr long) user32.UnregisterClassW