diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c
index a287a66d94e35189c2f7e226570e76d6e24f5925..7c40e653e526ca8d20165822c627c57ef6415c5c 100644
--- a/fs/orangefs/devorangefs-req.c
+++ b/fs/orangefs/devorangefs-req.c
@@ -17,6 +17,8 @@
 
 /* this file implements the /dev/pvfs2-req device node */
 
+uint32_t userspace_version;
+
 static int open_access_count;
 
 #define DUMP_DEVICE_ERROR()                                                   \
@@ -387,6 +389,13 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
 		return -EPROTO;
 	}
 
+	if (!userspace_version) {
+		userspace_version = head.version;
+	} else if (userspace_version != head.version) {
+		gossip_err("Error: userspace version changes\n");
+		return -EPROTO;
+	}
+
 	/* remove the op from the in progress hash table */
 	op = orangefs_devreq_remove_op(head.tag);
 	if (!op) {
@@ -527,6 +536,7 @@ static int orangefs_devreq_release(struct inode *inode, struct file *file)
 	gossip_debug(GOSSIP_DEV_DEBUG,
 		     "pvfs2-client-core: device close complete\n");
 	open_access_count = 0;
+	userspace_version = 0;
 	mutex_unlock(&devreq_mutex);
 	return 0;
 }
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 633c07a6e3d80530b585c957edc6d5eeae70d042..ff3566a8388f4c54a1ce45752aebdeeaac9ffded 100644
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -506,6 +506,8 @@ ssize_t orangefs_inode_read(struct inode *inode,
 /*
  * defined in devorangefs-req.c
  */
+extern uint32_t userspace_version;
+
 int orangefs_dev_init(void);
 void orangefs_dev_cleanup(void);
 int is_daemon_in_service(void);