--- rxvt-unicode/src/rxvttoolkit.C	2011/07/01 19:06:51	1.128
+++ rxvt-unicode/src/rxvttoolkit.C	2012/01/02 19:30:50	1.129
@@ -688,7 +688,7 @@
 rxvt_color::alloc (rxvt_screen *screen, const rgba &color)
 {
   //TODO: only supports 24 bit
-  int alpha = color.a >= 0xff00 ? 0xffff : color.a;
+  unsigned int alpha = color.a >= 0xff00 ? 0xffff : color.a;
 
 #if XFT
   XRenderPictFormat *format;