diff --git a/sys/dev/mlx5/mlx5_en/en.h b/sys/dev/mlx5/mlx5_en/en.h
index 04b7d3a59c6..1e9d4b0bc26 100644
--- a/sys/dev/mlx5/mlx5_en/en.h
+++ b/sys/dev/mlx5/mlx5_en/en.h
@@ -988,6 +988,7 @@ struct mlx5e_priv {
 #define	PRIV_LOCK(priv) sx_xlock(&(priv)->state_lock)
 #define	PRIV_UNLOCK(priv) sx_xunlock(&(priv)->state_lock)
 #define	PRIV_LOCKED(priv) sx_xlocked(&(priv)->state_lock)
+#define	PRIV_ASSERT_LOCKED(priv) sx_assert(&(priv)->state_lock, SA_XLOCKED)
 	struct sx state_lock;		/* Protects Interface state */
 	struct mlx5_uar cq_uar;
 	u32	pdn;
diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_flow_table.c b/sys/dev/mlx5/mlx5_en/mlx5_en_flow_table.c
index 88fb7f75374..dfbf9ff1de9 100644
--- a/sys/dev/mlx5/mlx5_en/mlx5_en_flow_table.c
+++ b/sys/dev/mlx5/mlx5_en/mlx5_en_flow_table.c
@@ -772,6 +772,8 @@ mlx5e_sync_ifp_addr(struct mlx5e_priv *priv)
 	struct ifaddr *ifa;
 	struct ifmultiaddr *ifma;
 
+	PRIV_ASSERT_LOCKED(priv);
+
 	/* XXX adding this entry might not be needed */
 	mlx5e_add_eth_addr_to_hash(priv->eth_addr.if_uc,
 	    LLADDR((struct sockaddr_dl *)(ifp->if_addr->ifa_addr)));