diff --git a/packages/node_modules/@node-red/nodes/core/network/31-tcpin.js b/packages/node_modules/@node-red/nodes/core/network/31-tcpin.js
index 9971a131eb..cbc42bff69 100644
--- a/packages/node_modules/@node-red/nodes/core/network/31-tcpin.js
+++ b/packages/node_modules/@node-red/nodes/core/network/31-tcpin.js
@@ -668,7 +668,15 @@ module.exports = function(RED) {
                             let event;
                             while (event = dequeue(clients[connection_id].msgQueue)) {
                                 if (event.msg.payload !== undefined) {
-                                    clients[connection_id].client.write(event.msg.payload);
+                                    if (typeof event.msg.payload !== 'string' && !Buffer.isBuffer(event.msg.payload) && !(event.msg.payload instanceof Uint8Array)) {
+                                        node.error(`TCP Out Invalid payload type: ${typeof event.msg.payload}. Expected Buffer, Uint8Array, or string.`, event.msg);
+                                    } else {
+                                        try {
+                                            clients[connection_id].client.write(event.msg.payload);
+                                        } catch (err) {
+                                            node.error(err, event.msg);
+                                        }
+                                    }
                                 }
                                 event.nodeDone();
                             }
@@ -870,7 +878,15 @@ module.exports = function(RED) {
                 if (clients[connection_id] && clients[connection_id].client) {
                     let event = dequeue(clients[connection_id].msgQueue)
                     if (event.msg.payload !== undefined ) {
-                        clients[connection_id].client.write(event.msg.payload);
+                        if (typeof event.msg.payload !== 'string' && !Buffer.isBuffer(event.msg.payload) && !(event.msg.payload instanceof Uint8Array)) {
+                            node.error(`TCP Out Invalid payload type: ${typeof event.msg.payload}. Expected Buffer, Uint8Array, or string.`, event.msg);
+                        } else {
+                            try {
+                                clients[connection_id].client.write(event.msg.payload);
+                            } catch (err) {
+                                node.error(err, event.msg);
+                            }
+                        }
                     }
                     event.nodeDone();
                 }
diff --git a/test/nodes/core/network/31-tcprequest_spec.js b/test/nodes/core/network/31-tcprequest_spec.js
index 154aa41654..c0669d462f 100644
--- a/test/nodes/core/network/31-tcprequest_spec.js
+++ b/test/nodes/core/network/31-tcprequest_spec.js
@@ -351,5 +351,34 @@ describe('TCP Request Node', function() {
                 topic: 'quux'
             }, done);
         });
+
+        it('should handle payload mutation to number during connection without crashing and log an error', function(done) {
+            var flow = [{id:"n1", type:"tcp request", server:"localhost", port:port, out:"time", splitc: "0", wires:[["n2"]] },
+                        {id:"n2", type:"helper"}];
+            helper.load(tcpinNode, flow, function() {
+                var n1 = helper.getNode("n1");
+                var msg = { payload: Buffer.from("foo") };
+                n1.receive(msg);
+                // Mutate the payload to a number synchronously after enqueue but before connection callback runs
+                msg.payload = 2;
+
+                setTimeout(function() {
+                    try {
+                        helper.log().called.should.be.true();
+                        var logEvents = helper.log().args.filter(function (evt) {
+                            return evt[0].type == "tcp request";
+                        });
+                        logEvents.should.have.length(1);
+                        var logMsg = logEvents[0][0];
+                        logMsg.should.have.property('level', helper.log().ERROR);
+                        logMsg.should.have.property('id', 'n1');
+                        logMsg.msg.should.containEql('Invalid payload type: number');
+                        done();
+                    } catch (err) {
+                        done(err);
+                    }
+                }, 100);
+            });
+        });
     });
 });