diff --git a/src/evalfunc.c b/src/evalfunc.c
index d902045..f6a3f9d 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -8359,9 +8359,15 @@
 	{
 	    if (switch_win_noblock(&switchwin, wp, tp, TRUE) == OK)
 	    {
+		// in diff mode, prevent that the window scrolls
+		// and keep the topline
+		if (curwin->w_p_diff && switchwin.sw_curwin->w_p_diff)
+		    skip_update_topline = TRUE;
 		check_cursor();
 		fp = var2fpos(&argvars[0], TRUE, &fnum, FALSE);
 	    }
+	    if (curwin->w_p_diff && switchwin.sw_curwin->w_p_diff)
+		skip_update_topline = FALSE;
 	    restore_win_noblock(&switchwin, TRUE);
 	}
     }