diff --git a/sys/netipsec/key.c b/sys/netipsec/key.c
--- a/sys/netipsec/key.c
+++ b/sys/netipsec/key.c
@@ -2961,8 +2961,8 @@
 		*errp = ENOBUFS;
 		goto done;
 	}
-	sav->lock = malloc(sizeof(struct mtx), M_IPSEC_MISC,
-	    M_NOWAIT | M_ZERO);
+	sav->lock = malloc_aligned(max(sizeof(struct mtx), CACHE_LINE_SIZE),
+	    CACHE_LINE_SIZE, M_IPSEC_MISC, M_NOWAIT | M_ZERO);
 	if (sav->lock == NULL) {
 		*errp = ENOBUFS;
 		goto done;