--- mount/umount.c
+++ mount/umount.c
@@ -40,7 +40,7 @@
 #include <linux/unistd.h>
 #ifdef __NR_umount2
 
-static int umount2(const char *path, int flags);
+int umount2(const char *path, int flags);
 
 _syscall2(int, umount2, const char *, path, int, flags);