diff --git a/compat.h b/compat.h
index 0693cf06..720cd909 100644
--- a/compat.h
+++ b/compat.h
@@ -336,11 +336,13 @@ void		*memmem(const void *, size_t, const void *, size_t);
 
 #ifndef HAVE_HTONLL
 /* htonll.c */
+#undef htonll
 uint64_t	 htonll(uint64_t);
 #endif
 
 #ifndef HAVE_NTOHLL
 /* ntohll.c */
+#undef ntohll
 uint64_t	 ntohll(uint64_t);
 #endif