diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S
index 4e5f0c5..1df0dcc 100644
--- a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S
+++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_rdlock.S
@@ -105,6 +105,7 @@ __pthread_rwlock_rdlock:
 	jmp	2b
 
 5:	xorl	%edx, %edx
+	LOCK
 	addl	$1, NR_READERS(%ebx)
 	je	8f
 9:	LOCK
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_unlock.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_unlock.S
index aabb929..7debc36 100644
--- a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_unlock.S
+++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_rwlock_unlock.S
@@ -52,6 +52,7 @@ __pthread_rwlock_unlock:
 
 2:	cmpl	$0, WRITER(%edi)
 	jne	5f
+	LOCK
 	subl	$1, NR_READERS(%edi)
 	jnz	6f