diff --git a/net/can/af_can.c b/net/can/af_can.c
index 1f51b8a18242..36b9f22ed83a 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -656,27 +656,27 @@ int can_proto_register(struct can_proto *cp)
 		return -EINVAL;
 	}
 
+	err = proto_register(cp->prot, 0);
+	if (err < 0)
+		return err;
+
 	spin_lock(&proto_tab_lock);
 	if (proto_tab[proto]) {
 		printk(KERN_ERR "can: protocol %d already registered\n",
 		       proto);
 		err = -EBUSY;
-		goto errout;
+	} else {
+		proto_tab[proto] = cp;
+
+		/* use generic ioctl function if not defined by module */
+		if (!cp->ops->ioctl)
+			cp->ops->ioctl = can_ioctl;
 	}
-
-	err = proto_register(cp->prot, 0);
-	if (err < 0)
-		goto errout;
-
-	proto_tab[proto] = cp;
-
-	/* use generic ioctl function if the module doesn't bring its own */
-	if (!cp->ops->ioctl)
-		cp->ops->ioctl = can_ioctl;
-
- errout:
 	spin_unlock(&proto_tab_lock);
 
+	if (err < 0)
+		proto_unregister(cp->prot);
+
 	return err;
 }
 EXPORT_SYMBOL(can_proto_register);
@@ -694,9 +694,10 @@ void can_proto_unregister(struct can_proto *cp)
 		printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
 		       proto);
 	}
-	proto_unregister(cp->prot);
 	proto_tab[proto] = NULL;
 	spin_unlock(&proto_tab_lock);
+
+	proto_unregister(cp->prot);
 }
 EXPORT_SYMBOL(can_proto_unregister);