diff --git a/dlls/comctl32/tests/trackbar.c b/dlls/comctl32/tests/trackbar.c
index ac67d50ed5d..8eaedf48e0d 100644
--- a/dlls/comctl32/tests/trackbar.c
+++ b/dlls/comctl32/tests/trackbar.c
@@ -527,6 +527,7 @@ static void test_line_size(HWND hWndTrackbar){
 
     /* test TBM_SETLINESIZE */
     r = SendMessage(hWndTrackbar, TBM_SETLINESIZE, 0, 10);
+    expect(1,r);
     r = SendMessage(hWndTrackbar, TBM_SETLINESIZE, 0, 4);
     expect(10, r);