Bug: https://rt.cpan.org/Public/Bug/Display.html?id=76442
Gentoo-Bug: https://bugs.gentoo.org/420177
--- a/src/C_XS/ToolBox.h
+++ b/src/C_XS/ToolBox.h
@@ -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