--- fvwm/modules/FvwmButtons/button.c
+++ fvwm/modules/FvwmButtons/button.c
@@ -490,13 +490,15 @@ void alloc_buttonlist(button_info *ub,int num)
   if(num>=ub->c->allocated_buttons)
   {
     old=ub->c->allocated_buttons;
-    if(num<old || old>(old+32)) /* test for num<old or for signed overflow */
-    {
-      fprintf(stderr,"%s: Too many buttons, integer overflow\n",MyName);
-      exit(1);
-    }
     while(ub->c->allocated_buttons<=num)
+    {
       ub->c->allocated_buttons+=32;
+      if(old>ub->c->allocated_buttons)
+      {
+	fprintf(stderr,"%s: Too many buttons, integer overflow\n",MyName);
+	exit(1);
+      }
+    }
     bb=(button_info**)
       mymalloc(ub->c->allocated_buttons*sizeof(button_info*));
     for(i=old;i<ub->c->allocated_buttons;i++)