--- rxvt-unicode/src/command.C	2023/05/06 06:47:29	1.601
+++ rxvt-unicode/src/command.C	2023/05/06 08:01:35	1.602
@@ -1283,8 +1283,8 @@
   int x, y;
   bool release = ev.type == ButtonRelease;
 
-  x = Pixel2Col (ev.x) + 1;
-  y = Pixel2Row (ev.y) + 1;
+  x = 1 + clamp (Pixel2Col (ev.x), 0, ncol - 1);
+  y = 1 + clamp (Pixel2Row (ev.y), 0, nrow - 1);
 
   if (ev.type == MotionNotify)
     {