diff --git a/lib/server.js b/lib/server.js
index a5c9fbb19..245937c19 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -890,7 +890,9 @@ Server.prototype._routeErrorResponse = function _routeErrorResponse(
         null,
         err,
         function _emitErrorEvents() {
-            res.send(err);
+            if (!res.headersSent) {
+                res.send(err);
+            }
             return self._finishReqResCycle(req, res, null, err);
         }
     );
diff --git a/test/server.test.js b/test/server.test.js
index 436906a78..7e3009e7b 100644
--- a/test/server.test.js
+++ b/test/server.test.js
@@ -224,6 +224,31 @@ test('rm route and clear cached route', function(t) {
     });
 });
 
+test('_routeErrorResponse does not cause uncaughtException when called when header has already been sent', function(
+    t
+) {
+    SERVER.on('MethodNotAllowed', function(req, res, error, next) {
+        res.json(405, { status: 'MethodNotAllowed' });
+        try {
+            next();
+        } catch (err) {
+            t.fail(
+                'next() should not throw error when header has already been sent'
+            );
+        }
+        t.end();
+    });
+
+    SERVER.post('/routePostOnly', function tester(req, res, next) {
+        next();
+    });
+
+    CLIENT.get('/routePostOnly', function(err, _, res) {
+        t.ok(err);
+        t.equal(res.statusCode, 405);
+    });
+});
+
 test('GH-1171: rm one version of the routes, other versions should still work', function(
     t
 ) {