diff --git a/libc/include/time64.h b/libc/include/time64.h
index 9da4bc7..7ec05af 100644
--- a/libc/include/time64.h
+++ b/libc/include/time64.h
@@ -31,9 +31,12 @@
 #ifndef TIME64_H
 #define TIME64_H
 
+#include <sys/cdefs.h>
 #include <time.h>
 #include <stdint.h>
 
+__BEGIN_DECLS
+
 typedef int64_t  time64_t;
 
 struct tm *gmtime64_r (const time64_t *, struct tm *);
@@ -51,4 +54,6 @@
 time64_t mktime64 (const struct tm *);
 time64_t timelocal64 (const struct tm *);
 
+__END_DECLS
+
 #endif /* TIME64_H */