diff --git a/serve.c b/serve.c
index db5ecfed2d..b3fe9b5126 100644
--- a/serve.c
+++ b/serve.c
@@ -201,7 +201,7 @@ static int receive_client_capability(const char *key)
 	const char *value;
 	const struct protocol_capability *c = get_capability(key, &value);
 
-	if (!c || !c->advertise(the_repository, NULL))
+	if (!c || c->command || !c->advertise(the_repository, NULL))
 		return 0;
 
 	if (c->receive)
diff --git a/t/t5701-git-serve.sh b/t/t5701-git-serve.sh
index 2e51886def..3928424e1b 100755
--- a/t/t5701-git-serve.sh
+++ b/t/t5701-git-serve.sh
@@ -72,6 +72,27 @@ test_expect_success 'request invalid command' '
 	test_i18ngrep "invalid command" err
 '
 
+test_expect_success 'request capability as command' '
+	test-tool pkt-line pack >in <<-EOF &&
+	command=agent
+	object-format=$(test_oid algo)
+	0000
+	EOF
+	test_must_fail test-tool serve-v2 --stateless-rpc 2>err <in &&
+	grep invalid.command.*agent err
+'
+
+test_expect_success 'request command as capability' '
+	test-tool pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	object-format=$(test_oid algo)
+	fetch
+	0000
+	EOF
+	test_must_fail test-tool serve-v2 --stateless-rpc 2>err <in &&
+	grep unknown.capability err
+'
+
 test_expect_success 'requested command is command=value' '
 	test-tool pkt-line pack >in <<-EOF &&
 	command=ls-refs=whatever