diff --git a/src/dd.c b/src/dd.c
index 20203fe..13e3262 100644
--- a/src/dd.c
+++ b/src/dd.c
@@ -882,6 +882,11 @@ HRESULT dd_SetDisplayMode(DWORD dwWidth, DWORD dwHeight, DWORD dwBPP, DWORD dwFl
     {
         g_ddraw.mouse.x_adjust = g_ddraw.render.viewport.x;
         g_ddraw.mouse.y_adjust = g_ddraw.render.viewport.y;
+
+    if (g_config.lock_mouse_top_left)
+    {
+        g_ddraw.mouse.x_adjust = 0;
+        g_ddraw.mouse.y_adjust = 0;
     }
 
     g_ddraw.mouse.rc.left = g_ddraw.mouse.x_adjust;