--- a\src\gtk\iupgtk_dialog.c	Wed Oct 11 19:38:34 2017
+++ b\src\gtk\iupgtk_dialog.c	Tue Jan 16 23:33:23 2018
@@ -1091,7 +1091,7 @@
     geometry.max_width = max_w-decorwidth;
 
   geometry.max_height = 65535;
-  if (max_h > decorheight && max_w > geometry.min_height)
+  if (max_h > decorheight && max_h > geometry.min_height)
     geometry.max_height = max_h-decorheight;
 
   /* must set both at the same time, or GTK will assume its default */