diff --git a/block/sheepdog.c b/block/sheepdog.c
index 696a71442a..459d93a35f 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1632,7 +1632,7 @@ static int sd_open(BlockDriverState *bs, QDict *options, int flags,
     if (!tag) {
         tag = "";
     }
-    if (tag && strlen(tag) >= SD_MAX_VDI_TAG_LEN) {
+    if (strlen(tag) >= SD_MAX_VDI_TAG_LEN) {
         error_setg(errp, "value of parameter 'tag' is too long");
         ret = -EINVAL;
         goto err_no_fd;