diff --git a/libc/include/sys/linux-unistd.h b/libc/include/sys/linux-unistd.h
index a1905b3..23853da 100644
--- a/libc/include/sys/linux-unistd.h
+++ b/libc/include/sys/linux-unistd.h
@@ -202,6 +202,7 @@
 int              inotify_add_watch (int, const char *, unsigned int);
 int              inotify_rm_watch (int, unsigned int);
 int              poll (struct pollfd *, unsigned int, long);
+int              eventfd (unsigned int, int);
 int              __set_tls (void*);
 int              cacheflush (long start, long end, long flags);
 #ifdef __cplusplus