diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c
index 3b69855..3538da1 100644
--- a/drivers/infiniband/hw/mthca/mthca_mr.c
+++ b/drivers/infiniband/hw/mthca/mthca_mr.c
@@ -686,7 +686,7 @@
 	mthca_table_put(dev, dev->mr_table.mpt_table, key);
 
 err_out_mpt_free:
-	mthca_free(&dev->mr_table.mpt_alloc, mr->ibmr.lkey);
+	mthca_free(&dev->mr_table.mpt_alloc, key);
 	return err;
 }