diff --git a/repo-settings.c b/repo-settings.c
index b93e91a212..27f230681f 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -82,6 +82,8 @@ void prepare_repo_settings(struct repository *r)
 			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
 		else if (!strcasecmp(strval, "noop"))
 			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_NOOP;
+		else if (!strcasecmp(strval, "default"))
+			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_DEFAULT;
 	}
 
 	/*
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 8a5d3492c7..bc29f03ce4 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -927,7 +927,8 @@ test_expect_success 'fetching deepen' '
 	)
 '
 
-test_expect_success 'use ref advertisement to prune "have" lines sent' '
+test_negotiation_algorithm_default () {
+	test_when_finished rm -rf clientv0 clientv2 &&
 	rm -rf server client &&
 	git init server &&
 	test_commit -C server both_have_1 &&
@@ -946,7 +947,7 @@ test_expect_success 'use ref advertisement to prune "have" lines sent' '
 	rm -f trace &&
 	cp -r client clientv0 &&
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C clientv0 \
-		fetch origin server_has both_have_2 &&
+		"$@" fetch origin server_has both_have_2 &&
 	grep "have $(git -C client rev-parse client_has)" trace &&
 	grep "have $(git -C client rev-parse both_have_2)" trace &&
 	! grep "have $(git -C client rev-parse both_have_2^)" trace &&
@@ -954,10 +955,20 @@ test_expect_success 'use ref advertisement to prune "have" lines sent' '
 	rm -f trace &&
 	cp -r client clientv2 &&
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C clientv2 -c protocol.version=2 \
-		fetch origin server_has both_have_2 &&
+		"$@" fetch origin server_has both_have_2 &&
 	grep "have $(git -C client rev-parse client_has)" trace &&
 	grep "have $(git -C client rev-parse both_have_2)" trace &&
 	! grep "have $(git -C client rev-parse both_have_2^)" trace
+}
+
+test_expect_success 'use ref advertisement to prune "have" lines sent' '
+	test_negotiation_algorithm_default
+'
+
+test_expect_success 'same as last but with config overrides' '
+	test_negotiation_algorithm_default \
+		-c feature.experimental=true \
+		-c fetch.negotiationAlgorithm=default
 '
 
 test_expect_success 'filtering by size' '