Index: src/strlcatu.h
===================================================================
--- src/strlcatu.h.orig 2014-04-25 14:52:18.365704085 +0200
+++ src/strlcatu.h 2014-04-25 14:54:45.169341645 +0200
@@ -21,6 +21,15 @@
 #ifndef __STRLCAT_H__
 #define __STRLCAT_H__
 
+#ifndef strlcat
+/*
+ * On OS X (and probably some other systems aswell), strlcat might be
+ * implemented as a macro. If this macro is defined while we're including this
+ * header, strlcat is already declared and trying to re-declare it with the
+ * following line *will* fail, because the macro will expand to something
+ * that's not a valid function name.
+ */
 size_t strlcat(char *, const char *, size_t);
+#endif /* !defined(strlcat) */
 
 #endif /* __STRLCAT_H__ */