diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 4d36e805a234..e41c2fa86d8b 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -34,6 +34,7 @@
 #include <linux/fs.h>
 #include <linux/proc_fs.h>
 #include <linux/compat.h>
+#include <linux/smp_lock.h>
 #include <asm/atomic.h>
 #include <asm/uaccess.h>
 #include <linux/hw_random.h>
@@ -300,7 +301,9 @@ static ssize_t zcrypt_write(struct file *filp, const char __user *buf,
  */
 static int zcrypt_open(struct inode *inode, struct file *filp)
 {
+	lock_kernel();
 	atomic_inc(&zcrypt_open_count);
+	unlock_kernel();
 	return 0;
 }