diff --git a/cmd/httpd/main.ha b/cmd/httpd/main.ha
index fb18942..48f9ec3 100644
--- a/cmd/httpd/main.ha
+++ b/cmd/httpd/main.ha
@@ -20,6 +20,8 @@ use thread;
 use time;
 
 type notfound = !void;
+type badrequest = !void;
+type http_err = !(notfound | badrequest);
 
 const usage: [_]getopt::help = [
 	"HTTP server",
@@ -84,11 +86,12 @@ fn handle_req(arg: nullable *opaque) void = {
 
 	match (route_request(&buf, serv_req)) {
 	case void => void;
+	case badrequest => handle_badrequest(&buf, serv_req);
 	case notfound => handle_notfound(&buf, serv_req);
 	};
 };
 
-fn route_request(buf: *io::stream, serv_req: *http::server_request) (void | notfound) = {
+fn route_request(buf: *io::stream, serv_req: *http::server_request) (void | http_err) = {
 	let request = &serv_req.request;
 	switch (request.method) {
 	case "GET" =>
@@ -174,8 +177,7 @@ fn handle_file(buf: *io::stream, serv_req: *http::server_request) (void | notfou
 	)!;
 };
 
-export fn handle_notfound(buf: *io::stream, request: *http::server_request) void = {
-	fmt::fprintfln(buf, "not found")!;
+fn handle_notfound(buf: *io::stream, request: *http::server_request) void = {
 	http::response_write(
 		request.socket,
 		http::STATUS_NOT_FOUND,
@@ -184,7 +186,16 @@ export fn handle_notfound(buf: *io::stream, request: *http::server_request) void
 	)!;
 };
 
-export fn handle_cors(buf: *io::stream, serv_req: *http::server_request) void = {
+fn handle_badrequest(buf: *io::stream, request: *http::server_request) void = {
+	http::response_write(
+		request.socket,
+		http::STATUS_BAD_REQUEST,
+		buf,
+		("Content-Type", "text/plain")
+	)!;
+};
+
+fn handle_cors(buf: *io::stream, serv_req: *http::server_request) void = {
 	let request = serv_req.request;
 
 	if (request.target.path == "/v1/exec") {
@@ -209,7 +220,7 @@ export fn handle_cors(buf: *io::stream, serv_req: *http::server_request) void =
 	)!;
 };
 
-fn handle_exec(buf: *io::stream, serv_req: *http::server_request) (void | notfound) = {
+fn handle_exec(buf: *io::stream, serv_req: *http::server_request) (void | badrequest) = {
 	let request = serv_req.request;
 
 	let payload = match (request.body) {
@@ -231,27 +242,27 @@ fn handle_exec(buf: *io::stream, serv_req: *http::server_request) (void | notfou
 
 	let payload = match (payload) {
 	case let obj: json::object => yield obj;
-	case => return notfound;
+	case => return badrequest;
 	};
 
 	let files = match (json::get(&payload, "files")) {
-	case void => return notfound;
+	case void => return badrequest;
 	case let j: *json::value => yield j;
 	};
 
 	let files = match (*files) {
 	case let o: json::object => yield o;
-	case => return notfound;
+	case => return badrequest;
 	};
 
 	let code = match (json::get(&files, "")) {
-	case void => return notfound;
+	case void => return badrequest;
 	case let j: *json::value => yield j;
 	};
 
 	let code = match (*code) {
 	case let c: str => yield c;
-	case => return notfound;
+	case => return badrequest;
 	};
 
 	let (stdout, stderr) = run_code(code);