diff -ur curl-7.33.0-clean/lib/pop3.h curl-7.33.0-modified/lib/pop3.h
--- curl-7.33.0-clean/lib/pop3.h	2013-10-12 13:24:12.000000000 -0700
+++ curl-7.33.0-modified/lib/pop3.h	2013-11-01 16:26:30.883479981 -0700
@@ -92,7 +92,7 @@
 
 /* Authentication type values */
 #define POP3_TYPE_NONE      0
-#define POP3_TYPE_ANY       ~0
+#define POP3_TYPE_ANY       ~0U
 
 /* This is the 5-bytes End-Of-Body marker for POP3 */
 #define POP3_EOB "\x0d\x0a\x2e\x0d\x0a"