diff -Nru Date-Pcalc-6.1.orig/src/C_XS/ToolBox.h Date-Pcalc-6.1/src/C_XS/ToolBox.h
--- Date-Pcalc-6.1.orig/src/C_XS/ToolBox.h	2009-10-15 18:31:02.000000000 +0200
+++ Date-Pcalc-6.1/src/C_XS/ToolBox.h	2012-11-16 19:33:58.120819087 +0100
@@ -93,7 +93,10 @@
     #elif PERL_DARWIN
         #define boolean bool
     #else
-        typedef enum { false = FALSE, true = TRUE } boolean;
+        typedef int boolean;
+        #ifndef I_STDBOOL
+         enum { false, true};
+        #endif
     #endif
 #endif