diff --git a/lib/response.js b/lib/response.js
index c01526e..f9b33d5 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -83,8 +83,8 @@ module.exports = {
   set status(code) {
     if (this.headerSent) return;
 
-    assert('number' == typeof code, 'status code must be a number');
-    assert(statuses[code], `invalid status code: ${code}`);
+    assert(Number.isInteger(code), 'status code must be a number');
+    assert(code >= 100 && code <= 999, `invalid status code: ${code}`);
     this._explicitStatus = true;
     this.res.statusCode = code;
     if (this.req.httpVersionMajor < 2) this.res.statusMessage = statuses[code];
diff --git a/test/response/status.js b/test/response/status.js
index 63e2ff6..af33948 100644
--- a/test/response/status.js
+++ b/test/response/status.js
@@ -24,8 +24,8 @@ describe('res.status=', () => {
     describe('and invalid', () => {
       it('should throw', () => {
         assert.throws(() => {
-          response().status = 999;
-        }, /invalid status code: 999/);
+          response().status = 99;
+        }, /invalid status code: 99/);
       });
     });