4 files changed, 22 insertions, 0 deletions
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index 1252d8500..d178512c5 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -2497,6 +2497,12 @@ console.log("finish");
     exit_code: 1,
   });
 
+  itest!(nonexistent_worker {
+    args: "run --allow-read workers/nonexistent_worker.ts",
+    output: "workers/nonexistent_worker.out",
+    exit_code: 1,
+  });
+
   #[test]
   fn compiler_api() {
     let status = util::deno_cmd()
diff --git a/cli/tests/workers/nonexistent_worker.out b/cli/tests/workers/nonexistent_worker.out
new file mode 100644
index 000000000..e43b81c5f
--- /dev/null
+++ b/cli/tests/workers/nonexistent_worker.out
@@ -0,0 +1,3 @@
+[WILDCARD]error: Uncaught (in worker "") Cannot resolve module "file:///[WILDCARD]cli/tests/workers/doesnt_exist.js".
+error: Uncaught (in promise) Error: Unhandled error event reached main worker.
+    at Worker.#poll ([WILDCARD])
diff --git a/cli/tests/workers/nonexistent_worker.ts b/cli/tests/workers/nonexistent_worker.ts
new file mode 100644
index 000000000..8ebe29114
--- /dev/null
+++ b/cli/tests/workers/nonexistent_worker.ts
@@ -0,0 +1,5 @@
+const w = new Worker(new URL("doesnt_exist.js", import.meta.url).href, {
+  type: "module",
+});
+
+w.postMessage("hello");
diff --git a/runtime/web_worker.rs b/runtime/web_worker.rs
index 68bbe1a5d..8c8761d62 100644
--- a/runtime/web_worker.rs
+++ b/runtime/web_worker.rs
@@ -67,6 +67,14 @@ impl WebWorkerHandle {
   /// Post message to worker as a host.
   pub fn post_message(&self, buf: Box<[u8]>) -> Result<(), AnyError> {
     let mut sender = self.sender.clone();
+    // If the channel is closed,
+    // the worker must have terminated but the termination message has not yet been recieved.
+    //
+    // Therefore just treat it as if the worker has terminated and return.
+    if sender.is_closed() {
+      self.terminated.store(true, Ordering::SeqCst);
+      return Ok(());
+    }
     sender.try_send(buf)?;
     Ok(())
   }