diff --git a/src/evalfunc.c b/src/evalfunc.c
index 2be7fe1..4521835 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -4382,6 +4382,8 @@
 		/* Find the window at the mouse coordinates and compute the
 		 * text position. */
 		win = mouse_find_win(&row, &col);
+		if (win == NULL)
+		    return;
 		(void)mouse_comp_pos(win, &row, &col, &lnum);
 # ifdef FEAT_WINDOWS
 		for (wp = firstwin; wp != win; wp = wp->w_next)