diff --git a/utils/imxtools/sbtools/aes128.c b/utils/imxtools/sbtools/aes128.c
index 5870813db8..af3d48761c 100644
--- a/utils/imxtools/sbtools/aes128.c
+++ b/utils/imxtools/sbtools/aes128.c
@@ -280,5 +280,7 @@ void cbc_mac(
             /* copy cipher to iv */
             memcpy(feedback, &in_data[i * 16], 16);
         }
+        if(out_cbc_mac)
+            memcpy(out_cbc_mac, feedback, 16);
     }
 }