diff --git a/dlls/dinput/device.c b/dlls/dinput/device.c
index 17eaff69d50..2a3ed391919 100644
--- a/dlls/dinput/device.c
+++ b/dlls/dinput/device.c
@@ -1094,6 +1094,7 @@ HRESULT WINAPI IDirectInputDevice2WImpl_SetDataFormat(LPDIRECTINPUTDEVICE8W ifac
     _dump_DIDATAFORMAT(df);
 
     if (df->dwSize != sizeof(DIDATAFORMAT)) return DIERR_INVALIDPARAM;
+    if (df->dwObjSize != sizeof(DIOBJECTDATAFORMAT)) return DIERR_INVALIDPARAM;
     if (This->acquired) return DIERR_ACQUIRED;
 
     EnterCriticalSection(&This->crit);
diff --git a/dlls/dinput8/tests/hid.c b/dlls/dinput8/tests/hid.c
index 371edc99251..e017e048a30 100644
--- a/dlls/dinput8/tests/hid.c
+++ b/dlls/dinput8/tests/hid.c
@@ -4015,7 +4015,6 @@ static void test_simple_joystick(void)
     ok( hr == DIERR_INVALIDPARAM, "IDirectInputDevice8_SetDataFormat returned: %#x\n", hr );
     dataformat.dwSize = sizeof(DIDATAFORMAT);
     hr = IDirectInputDevice8_SetDataFormat( device, &dataformat );
-    todo_wine
     ok( hr == DIERR_INVALIDPARAM, "IDirectInputDevice8_SetDataFormat returned: %#x\n", hr );
     dataformat.dwObjSize = sizeof(DIOBJECTDATAFORMAT);
     hr = IDirectInputDevice8_SetDataFormat( device, &dataformat );