diff --git a/sys/dev/cxgbe/t4_main.c b/sys/dev/cxgbe/t4_main.c
index 4f9172144600..09ea9d2f9704 100644
--- a/sys/dev/cxgbe/t4_main.c
+++ b/sys/dev/cxgbe/t4_main.c
@@ -3432,6 +3432,7 @@ adapter_full_init(struct adapter *sc)
 {
 	int rc, i;
 
+	ASSERT_SYNCHRONIZED_OP(sc);
 	ADAPTER_LOCK_ASSERT_NOTOWNED(sc);
 	KASSERT((sc->flags & FULL_INIT_DONE) == 0,
 	    ("%s: FULL_INIT_DONE already", __func__));