diff --git a/src/legacy/core_plugins/interpreter/server/lib/route_expression/thread/index.js b/src/legacy/core_plugins/interpreter/server/lib/route_expression/thread/index.js
index ff476793325e..942d0c66dc81 100644
--- a/src/legacy/core_plugins/interpreter/server/lib/route_expression/thread/index.js
+++ b/src/legacy/core_plugins/interpreter/server/lib/route_expression/thread/index.js
@@ -31,15 +31,7 @@ export function getWorker() {
   if (worker) return worker;
   worker = fork(workerPath, {});
 
-  // 'exit' happens whether we kill the worker or it just dies.
-  // No need to look for 'error', our worker is intended to be long lived so it isn't running, it's an issue
-  worker.on('exit', () => {
-    // Heads up: there is no worker.off
-    worker = null;
-    // Restart immediately on exit since node takes a couple seconds to spin up
-    worker = getWorker();
-  });
-
+  // handle run requests
   worker.on('message', msg => {
     const { type, value, id } = msg;
     if (type === 'run') {
@@ -59,6 +51,18 @@ export function getWorker() {
     if (type === 'msgError' && heap[id]) heap[id].reject(new Error(value));
   });
 
+  // handle exit event, fired when we kill the worker or it just dies
+  worker.on('exit', () => {
+    // NOTE: No need to look for 'code' or 'signal', if it isn't running, it's an issue
+
+    // clean up any listeners on the worker before replacing it
+    worker.removeAllListeners();
+
+    // Restart immediately on exit since node takes a couple seconds to spin up
+    worker = null;
+    worker = getWorker();
+  });
+
   return worker;
 }
 
@@ -66,10 +70,18 @@ export function getWorker() {
 export const thread = ({ onFunctionNotFound, serialize, deserialize }) => {
   const getWorkerFunctions = new Promise(resolve => {
     const worker = getWorker();
+
+    function functionListHandler(msg) {
+      // wait for the function list message
+      if (msg.type === 'functionList') {
+        // tear dowm the listener once the function list is provided
+        worker.removeListener('message', functionListHandler);
+        resolve(msg.value);
+      }
+    }
+    worker.on('message', functionListHandler);
+
     worker.send({ type: 'getFunctions' });
-    worker.on('message', msg => {
-      if (msg.type === 'functionList') resolve(msg.value);
-    });
   });
 
   return getWorkerFunctions.then(functions => {
@@ -94,7 +106,7 @@ export const thread = ({ onFunctionNotFound, serialize, deserialize }) => {
               onFunctionNotFound(ast, deserialize(context)).then(serialize),
           };
 
-          //
+          // kill the worker after the timeout is exceeded
           setTimeout(() => {
             if (!heap[id]) return; // Looks like this has already been cleared from the heap.
             if (worker) worker.kill();
diff --git a/src/legacy/core_plugins/interpreter/server/routes/socket.js b/src/legacy/core_plugins/interpreter/server/routes/socket.js
index 80733690a7d1..8befd511937e 100644
--- a/src/legacy/core_plugins/interpreter/server/routes/socket.js
+++ b/src/legacy/core_plugins/interpreter/server/routes/socket.js
@@ -75,7 +75,7 @@ export function socketApi(server) {
       );
     });
 
-    const handler = async ({ ast, context, id }) => {
+    socket.on('run', async ({ ast, context, id }) => {
       try {
         const value = await routeExpression(ast, deserialize(context));
         socket.emit(`resp:${id}`, { type: 'msgSuccess', value: serialize(value) });
@@ -83,11 +83,11 @@ export function socketApi(server) {
         // TODO: I don't think it is possible to hit this right now? Maybe ever?
         socket.emit(`resp:${id}`, { type: 'msgError', value: err });
       }
-    };
+    });
 
-    socket.on('run', handler);
     socket.on('disconnect', () => {
-      socket.removeListener('run', handler);
+      // remove all listeners on disconnect
+      socket.removeAllListeners();
     });
   });
 }