--- UsageEnvironment/include/Boolean.hh.orig	2012-04-12 12:25:13.000000000 -0700
+++ UsageEnvironment/include/Boolean.hh	2012-04-12 12:26:38.000000000 -0700
@@ -21,7 +21,11 @@
 #define False false
 #define True true
 #else
+#ifdef __APPLE__
+typedef unsigned char Boolean;
+#else
 typedef unsigned Boolean;
+#endif
 #ifndef __MSHTML_LIBRARY_DEFINED__
 #ifndef False
 const Boolean False = 0;