diff --git a/dlls/user/tests/monitor.c b/dlls/user/tests/monitor.c
index 82831bd268f..157649aa7a3 100644
--- a/dlls/user/tests/monitor.c
+++ b/dlls/user/tests/monitor.c
@@ -97,9 +97,59 @@ static void test_enumdisplaydevices(void)
     }
 }
 
+struct vid_mode
+{
+    DWORD w, h, bpp, freq, fields;
+    LONG res;
+};
+
+static struct vid_mode vid_modes_test[] = {
+    {640, 480, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_DISPLAYFREQUENCY, DISP_CHANGE_SUCCESSFUL},
+    {640, 480, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT |                 DM_DISPLAYFREQUENCY, DISP_CHANGE_SUCCESSFUL},
+    {640, 480, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL                      , DISP_CHANGE_SUCCESSFUL},
+    {640, 480, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT                                      , DISP_CHANGE_SUCCESSFUL},
+    {640, 480, 0, 0,                                DM_BITSPERPEL                      , DISP_CHANGE_SUCCESSFUL},
+    {640, 480, 0, 0,                                                DM_DISPLAYFREQUENCY, DISP_CHANGE_SUCCESSFUL},
+
+    {0, 0, 0, 0, DM_PELSWIDTH, DISP_CHANGE_SUCCESSFUL},
+    {0, 0, 0, 0, DM_PELSHEIGHT, DISP_CHANGE_SUCCESSFUL},
+
+    {640, 480, 0, 0, DM_PELSWIDTH, DISP_CHANGE_BADMODE},
+    {640, 480, 0, 0, DM_PELSHEIGHT, DISP_CHANGE_BADMODE},
+    {  0, 480, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT, DISP_CHANGE_BADMODE},
+    {640,   0, 0, 0, DM_PELSWIDTH | DM_PELSHEIGHT, DISP_CHANGE_BADMODE},
+
+    {0, 0, 0, 10, DM_DISPLAYFREQUENCY, DISP_CHANGE_BADMODE},
+};
+#define vid_modes_cnt (sizeof(vid_modes_test) / sizeof(vid_modes_test[0]))
+
+static void test_ChangeDisplaySettingsEx(void)
+{
+    DEVMODE dm;
+    LONG res;
+    int i;
+
+    memset(&dm, 0, sizeof(dm));
+    dm.dmSize = sizeof(dm);
+
+    for (i = 0; i < vid_modes_cnt; i++)
+    {
+        dm.dmPelsWidth        = vid_modes_test[i].w;
+        dm.dmPelsHeight       = vid_modes_test[i].h;
+        dm.dmBitsPerPel       = vid_modes_test[i].bpp;
+        dm.dmDisplayFrequency = vid_modes_test[i].freq;
+        dm.dmFields           = vid_modes_test[i].fields;
+        res = ChangeDisplaySettingsEx(NULL, &dm, NULL, CDS_FULLSCREEN, NULL);
+        ok(res == vid_modes_test[i].res, "Failed to change resolution[%d]: %ld\n", i, res);
+    }
+    res = ChangeDisplaySettingsEx(NULL, NULL, NULL, CDS_RESET, NULL);
+    ok(res == DISP_CHANGE_SUCCESSFUL, "Failed to reset default resolution: %ld\n", res);
+}
+
 
 START_TEST(monitor)
 {
     init_function_pointers();
     test_enumdisplaydevices();
+    test_ChangeDisplaySettingsEx();
 }
diff --git a/dlls/winex11.drv/settings.c b/dlls/winex11.drv/settings.c
index 95e88e61088..49b8a8d5db0 100644
--- a/dlls/winex11.drv/settings.c
+++ b/dlls/winex11.drv/settings.c
@@ -237,8 +237,9 @@ static const char * _DM_fields(DWORD fields)
 LONG X11DRV_ChangeDisplaySettingsEx( LPCWSTR devname, LPDEVMODEW devmode,
                                      HWND hwnd, DWORD flags, LPVOID lpvoid )
 {
-    DWORD i, dwBpp;
+    DWORD i, dwBpp = 0;
     DEVMODEW dm;
+    BOOL def_mode = TRUE;
 
     TRACE("(%s,%p,%p,0x%08lx,%p)\n",debugstr_w(devname),devmode,hwnd,flags,lpvoid);
     TRACE("flags=%s\n",_CDS_flags(flags));
@@ -248,8 +249,15 @@ LONG X11DRV_ChangeDisplaySettingsEx( LPCWSTR devname, LPDEVMODEW devmode,
         TRACE("width=%ld height=%ld bpp=%ld freq=%ld (%s)\n",
               devmode->dmPelsWidth,devmode->dmPelsHeight,
               devmode->dmBitsPerPel,devmode->dmDisplayFrequency, handler_name);
+
+        dwBpp = (devmode->dmBitsPerPel == 24) ? 32 : devmode->dmBitsPerPel;
+        if (devmode->dmFields & DM_BITSPERPEL) def_mode &= !dwBpp;
+        if (devmode->dmFields & DM_PELSWIDTH)  def_mode &= !devmode->dmPelsWidth;
+        if (devmode->dmFields & DM_PELSHEIGHT) def_mode &= !devmode->dmPelsHeight;
+        if (devmode->dmFields & DM_DISPLAYFREQUENCY) def_mode &= !devmode->dmDisplayFrequency;
     }
-    else
+
+    if (def_mode)
     {
         TRACE("Return to original display mode (%s)\n", handler_name);
         if (!X11DRV_EnumDisplaySettingsEx(devname, dd_mode_default, &dm, 0))
@@ -259,7 +267,10 @@ LONG X11DRV_ChangeDisplaySettingsEx( LPCWSTR devname, LPDEVMODEW devmode,
         }
         devmode = &dm;
     }
-    dwBpp = (devmode->dmBitsPerPel == 24) ? 32 : devmode->dmBitsPerPel;
+    dwBpp = !dwBpp ? dd_modes[dd_mode_default].dwBPP : dwBpp;
+
+    if ((devmode->dmFields & (DM_PELSWIDTH | DM_PELSHEIGHT)) != (DM_PELSWIDTH | DM_PELSHEIGHT))
+        return DISP_CHANGE_BADMODE;
 
     for (i = 0; i < dd_mode_count; i++)
     {
@@ -278,7 +289,8 @@ LONG X11DRV_ChangeDisplaySettingsEx( LPCWSTR devname, LPDEVMODEW devmode,
             if (devmode->dmPelsHeight != dd_modes[i].dwHeight)
                 continue;
         }
-        if ((devmode->dmFields & DM_DISPLAYFREQUENCY) && (dd_modes[i].wRefreshRate != 0))
+        if ((devmode->dmFields & DM_DISPLAYFREQUENCY) && (dd_modes[i].wRefreshRate != 0) &&
+            devmode->dmDisplayFrequency != 0)
         {
             if (devmode->dmDisplayFrequency != dd_modes[i].wRefreshRate)
                 continue;