diff --git a/lib/chain.js b/lib/chain.js
index c1c08cb6..f1fc5caf 100644
--- a/lib/chain.js
+++ b/lib/chain.js
@@ -140,7 +140,7 @@ Chain.prototype.run = function run(req, res, done) {
         var handler = self._stack[index++];
 
         // all done or request closed
-        if (!handler || req.closed()) {
+        if (!handler || req.connectionState() === 'close') {
             process.nextTick(function nextTick() {
                 return done(err, req, res);
             });
diff --git a/lib/plugins/static.js b/lib/plugins/static.js
index 0fcdfd26..0fa6babe 100644
--- a/lib/plugins/static.js
+++ b/lib/plugins/static.js
@@ -93,7 +93,10 @@ function serveStatic(options) {
     var re = new RegExp('^' + escapeRE(p) + '/?.*');
 
     function serveFileFromStats(file, err, stats, isGzip, req, res, next) {
-        if (typeof req.closed === 'function' && req.closed()) {
+        if (
+            typeof req.connectionState === 'function' &&
+            req.connectionState() === 'close'
+        ) {
             next(false);
             return;
         }
diff --git a/lib/request.js b/lib/request.js
index eddd0591..a4c54d0e 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -2,6 +2,7 @@
 
 'use strict';
 
+const { emitWarning } = require('node:process');
 var url = require('url');
 var sprintf = require('util').format;
 
@@ -846,6 +847,11 @@ function patch(Request) {
      * @returns {Boolean} is closed
      */
     Request.prototype.closed = function closed() {
+        emitWarning(
+            'restify req.closed is deprecated, will be removed on Restify 10',
+            'RestifyDeprecationWarning',
+            'RestifyDEPReqClosed'
+        );
         var self = this;
         return self.connectionState() === 'close';
     };
diff --git a/test/chain.test.js b/test/chain.test.js
index 403cf0d2..494a2a2f 100644
--- a/test/chain.test.js
+++ b/test/chain.test.js
@@ -29,8 +29,8 @@ test('calls all the handlers', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -58,8 +58,8 @@ test('abort with Error in next', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -85,7 +85,7 @@ test('abort with false in next', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
+            connectionState: function() {
                 return false;
             }
         },
@@ -112,8 +112,8 @@ test('abort with closed request', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return closed;
+            connectionState: function() {
+                return closed ? 'close' : '';
             }
         },
         {},
@@ -143,8 +143,8 @@ test('cals error middleware', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -170,8 +170,8 @@ test('onceNext prevents double next calls', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -208,8 +208,8 @@ test('throws error for double next calls in strictNext mode', function(t) {
             {
                 startHandlerTimer: function() {},
                 endHandlerTimer: function() {},
-                closed: function() {
-                    return false;
+                connectionState: function() {
+                    return '';
                 }
             },
             {},
@@ -234,8 +234,8 @@ test('calls req.startHandlerTimer', function(t) {
                 t.done();
             },
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -257,8 +257,8 @@ test('calls req.endHandlerTimer', function(t) {
                 t.equal(handleName, 'foo');
                 t.done();
             },
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -299,8 +299,8 @@ test('waits async handlers', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -329,8 +329,8 @@ test('abort with rejected promise', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -359,8 +359,8 @@ test('abort with rejected promise without error', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             },
             path: function() {
                 return '/';
@@ -395,8 +395,8 @@ test('abort with throw inside async function', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
diff --git a/test/chainComposer.test.js b/test/chainComposer.test.js
index 63fddb4a..6259f2a7 100644
--- a/test/chainComposer.test.js
+++ b/test/chainComposer.test.js
@@ -29,8 +29,8 @@ test('chainComposer creates a valid chain for a handler array ', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
@@ -53,8 +53,8 @@ test('chainComposer creates a valid chain for a single handler', function(t) {
         {
             startHandlerTimer: function() {},
             endHandlerTimer: function() {},
-            closed: function() {
-                return false;
+            connectionState: function() {
+                return '';
             }
         },
         {},
diff --git a/test/request.test.js b/test/request.test.js
index 44764505..a2d216fb 100644
--- a/test/request.test.js
+++ b/test/request.test.js
@@ -275,3 +275,27 @@ test('should emit restifyDone event when request is fully served with error', fu
         clientDone = true;
     });
 });
+
+test('should emit warning if closed is called', function(t) {
+    let warningCalled = false;
+    SERVER.get('/ping/:name', function(req, res, next) {
+        function testWarning(warning) {
+            t.equal(warning.name, 'RestifyDeprecationWarning');
+            t.equal(warning.code, 'RestifyDEPReqClosed');
+            t.ok(warning.stack);
+            warningCalled = true;
+
+            res.send('ok');
+            return next();
+        }
+        process.once('warning', testWarning);
+        t.notOk(req.closed());
+    });
+
+    CLIENT.get('/ping/lagavulin', function(err, _, res) {
+        t.ifError(err);
+        t.equal(res.statusCode, 200);
+        t.ok(warningCalled);
+        t.end();
+    });
+});
diff --git a/test/router.test.js b/test/router.test.js
index c1a8132e..fc49979a 100644
--- a/test/router.test.js
+++ b/test/router.test.js
@@ -16,8 +16,8 @@ var helper = require('./lib/helper.js');
 var test = helper.test;
 var mockReq = {
     params: {},
-    closed: function() {
-        return false;
+    connectionState: function() {
+        return '';
     },
     startHandlerTimer: function() {},
     endHandlerTimer: function() {}