diff --git a/rostests/apitests/user32/CreateWindowEx.c b/rostests/apitests/user32/CreateWindowEx.c
index d708e3aac4c..9c93df799ce 100644
--- a/rostests/apitests/user32/CreateWindowEx.c
+++ b/rostests/apitests/user32/CreateWindowEx.c
@@ -14,6 +14,19 @@ START_TEST(CreateWindowEx)
     HWND hWnd;
     DWORD dwError;
 
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd != NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == 0, "error = %lu\n", dwError);
+    DestroyWindow(hWnd);
+
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, 0, 0, 0, 0, 0, (HWND)(LONG_PTR)-1, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd == NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == ERROR_INVALID_WINDOW_HANDLE, "error = %lu\n", dwError);
+
     SetLastError(0x1234);
     hWnd = CreateWindowExW(0, L"BUTTON", NULL, WS_CHILD, 0, 0, 0, 0, NULL, NULL, NULL, NULL);
     dwError = GetLastError();
@@ -25,4 +38,30 @@ START_TEST(CreateWindowEx)
     dwError = GetLastError();
     ok(hWnd == NULL, "hWnd = %p\n", hWnd);
     ok(dwError == ERROR_INVALID_WINDOW_HANDLE, "error = %lu\n", dwError);
+
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, WS_POPUP, 0, 0, 0, 0, NULL, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd != NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == 0, "error = %lu\n", dwError);
+    DestroyWindow(hWnd);
+
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, WS_POPUP, 0, 0, 0, 0, (HWND)(LONG_PTR)-1, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd == NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == ERROR_INVALID_WINDOW_HANDLE, "error = %lu\n", dwError);
+
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, WS_CHILD|WS_POPUP, 0, 0, 0, 0, NULL, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd != NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == 0, "error = %lu\n", dwError);
+    DestroyWindow(hWnd);
+
+    SetLastError(0x1234);
+    hWnd = CreateWindowExW(0, L"BUTTON", NULL, WS_CHILD|WS_POPUP, 0, 0, 0, 0, (HWND)(LONG_PTR)-1, NULL, NULL, NULL);
+    dwError = GetLastError();
+    ok(hWnd == NULL, "hWnd = %p\n", hWnd);
+    ok(dwError == ERROR_INVALID_WINDOW_HANDLE, "error = %lu\n", dwError);
 }