diff --git a/sysdeps/unix/sysv/linux/alpha/semctl.c b/sysdeps/unix/sysv/linux/alpha/semctl.c
index a4534744d3..4be4fb201a 100644
--- a/sysdeps/unix/sysv/linux/alpha/semctl.c
+++ b/sysdeps/unix/sysv/linux/alpha/semctl.c
@@ -49,6 +49,7 @@ union semun
   struct seminfo *__buf;	/* buffer for IPC_INFO */
 };
 
+extern int __syscall_semctl (int, int, int, void *);
 
 /* Return identifier for array of NSEMS semaphores associated with
    KEY.  */