diff --git a/libc/include/bits/fcntl.h b/libc/include/bits/fcntl.h
index 604d35a..e3b0e8c 100644
--- a/libc/include/bits/fcntl.h
+++ b/libc/include/bits/fcntl.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-int fcntl(int, int, ...);
+int fcntl(int __fd, int __cmd, ...);
 
 __END_DECLS