--- rxvt-unicode/src/main.C	2008/02/19 13:01:32	1.308
+++ rxvt-unicode/src/main.C	2008/02/27 01:02:33	1.309
@@ -561,6 +561,9 @@
                 szHint.win_gravity = SouthWestGravity;
             }
         }
+
+      if (!szHint.width || !szHint.height)
+        rxvt_fatal ("window width or height must not be zero, aborting.\n");
     }
 
   /* TODO: BOUNDS */