diff --git a/eslint.config.mjs b/eslint.config.mjs
index 9cdd1157b2c66..84f59b4d0173b 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -28,6 +28,7 @@ export default [{
     'src/polyfill/',
     'src/lib/',
     'src/binaryDecode.js',
+    'src/build_as_worker.js',
     'src/minimum_runtime_check.js',
     'src/runtime_*.js',
     'src/shell*.js',
diff --git a/src/build_as_worker.js b/src/build_as_worker.js
new file mode 100644
index 0000000000000..51d6bd5053cd0
--- /dev/null
+++ b/src/build_as_worker.js
@@ -0,0 +1,51 @@
+var workerResponded = false, workerCallbackId = -1;
+
+(() => {
+  var messageBuffer = null, buffer = 0;
+
+  function flushMessages() {
+    if (!messageBuffer) return;
+    if (runtimeInitialized) {
+      var temp = messageBuffer;
+      messageBuffer = null;
+      temp.forEach((message) => onmessage(message));
+    }
+  }
+
+  function messageResender() {
+    flushMessages();
+    if (messageBuffer) {
+      setTimeout(messageResender, 100); // still more to do
+    }
+  }
+
+  onmessage = (msg) => {
+    // if main has not yet been called (mem init file, other async things), buffer messages
+    if (!runtimeInitialized) {
+      if (!messageBuffer) {
+        messageBuffer = [];
+        setTimeout(messageResender, 100);
+      }
+      messageBuffer.push(msg);
+      return;
+    }
+    flushMessages();
+
+    var func = Module['_' + msg.data['funcName']];
+    if (!func) abort('invalid worker function to call: ' + msg.data['funcName']);
+    var data = msg.data['data'];
+    if (data) {
+      if (!data.byteLength) data = new Uint8Array(data);
+      buffer = _realloc(buffer, data.length);
+      HEAPU8.set(data, buffer);
+    }
+
+    workerResponded = false;
+    workerCallbackId = msg.data['callbackId'];
+    if (data) {
+      func(buffer, data.length);
+    } else {
+      func(0, 0);
+    }
+  }
+})();
diff --git a/src/postamble.js b/src/postamble.js
index 414ab920ff616..d0ecc3b16bed3 100644
--- a/src/postamble.js
+++ b/src/postamble.js
@@ -373,59 +373,3 @@ run();
 #endif
 
 #endif // MODULARIZE != instance
-
-#if BUILD_AS_WORKER
-
-var workerResponded = false, workerCallbackId = -1;
-
-(() => {
-  var messageBuffer = null, buffer = 0;
-
-  function flushMessages() {
-    if (!messageBuffer) return;
-    if (runtimeInitialized) {
-      var temp = messageBuffer;
-      messageBuffer = null;
-      temp.forEach((message) => onmessage(message));
-    }
-  }
-
-  function messageResender() {
-    flushMessages();
-    if (messageBuffer) {
-      setTimeout(messageResender, 100); // still more to do
-    }
-  }
-
-  onmessage = (msg) => {
-    // if main has not yet been called (mem init file, other async things), buffer messages
-    if (!runtimeInitialized) {
-      if (!messageBuffer) {
-        messageBuffer = [];
-        setTimeout(messageResender, 100);
-      }
-      messageBuffer.push(msg);
-      return;
-    }
-    flushMessages();
-
-    var func = Module['_' + msg.data['funcName']];
-    if (!func) abort('invalid worker function to call: ' + msg.data['funcName']);
-    var data = msg.data['data'];
-    if (data) {
-      if (!data.byteLength) data = new Uint8Array(data);
-      buffer = _realloc(buffer, data.length);
-      HEAPU8.set(data, buffer);
-    }
-
-    workerResponded = false;
-    workerCallbackId = msg.data['callbackId'];
-    if (data) {
-      func(buffer, data.length);
-    } else {
-      func(0, 0);
-    }
-  }
-})();
-
-#endif
diff --git a/tools/link.py b/tools/link.py
index 532c072591f63..20787b822bb74 100644
--- a/tools/link.py
+++ b/tools/link.py
@@ -1715,9 +1715,10 @@ def limit_incoming_module_api():
     # need to be able to call these explicitly.
     settings.REQUIRED_EXPORTS += ['__funcs_on_exit']
 
-  # The worker code in src/postamble.js depends on realloc
   if settings.BUILD_AS_WORKER:
+    # The worker code in src/build_as_worker.js depends on realloc
     settings.REQUIRED_EXPORTS += ['realloc']
+    options.post_js.append(utils.path_from_root('src/build_as_worker.js'))
 
   if not settings.DISABLE_EXCEPTION_CATCHING:
     settings.REQUIRED_EXPORTS += [