diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c
index e2889967036a..980ef13b4cf6 100644
--- a/drivers/misc/mic/scif/scif_rma.c
+++ b/drivers/misc/mic/scif/scif_rma.c
@@ -680,6 +680,7 @@ int scif_unregister_window(struct scif_window *window)
 			}
 		} else {
 			/* Return ENXIO since unregistration is in progress */
+			mutex_lock(&ep->rma_info.rma_lock);
 			return -ENXIO;
 		}
 retry: