diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 716c9dbb69..4191174584 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -55,7 +55,7 @@ test_expect_success 'clone http repository' '
 	< content-type: application/x-git-upload-pack-result
 	EOF
 
-	GIT_TRACE_CURL=true GIT_TEST_PROTOCOL_VERSION=0 LANGUAGE="ko_KR.UTF-8" \
+	GIT_TRACE_CURL=true LANGUAGE="ko_KR.UTF-8" \
 		git clone --quiet $HTTPD_URL/smart/repo.git clone 2>err &&
 	test_cmp file clone/file &&
 	tr '\''\015'\'' Q <err |