diff --git a/sys/dev/raid/aac/aac.c b/sys/dev/raid/aac/aac.c
--- a/sys/dev/raid/aac/aac.c
+++ b/sys/dev/raid/aac/aac.c
@@ -610,7 +610,8 @@
 	if (sc->aac_fib_dmat)
 		bus_dma_tag_destroy(sc->aac_fib_dmat);
 
-	kfree(sc->aac_commands, M_AACBUF);
+	if (sc->aac_commands != NULL)
+		kfree(sc->aac_commands, M_AACBUF);
 
 	/* destroy the common area */
 	if (sc->aac_common) {