diff --git a/src/client.ts b/src/client.ts
index 5dc48a96..e87d1ad2 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -518,8 +518,8 @@ export function createClient(options: ClientOptions): Client {
             );
 
             releaserRef.current = () => {
-              if (!completed) {
-                // if not completed already, send complete message to server on release
+              if (!completed && socket.readyState === WebSocketImpl.OPEN) {
+                // if not completed already and socket is open, send complete message to server on release
                 socket.send(
                   stringifyMessage<MessageType.Complete>({
                     id: id,
diff --git a/src/tests/client.ts b/src/tests/client.ts
index 1a8a4b4d..3f235695 100644
--- a/src/tests/client.ts
+++ b/src/tests/client.ts
@@ -284,6 +284,47 @@ it('should close the socket if the `connectionParams` rejects or throws', async
   });
 });
 
+it('should not send the complete message if the socket is not open', async () => {
+  const {
+    url,
+    clients,
+    waitForOperation,
+    waitForClientClose,
+  } = await startTServer();
+
+  class MockWebSocket extends WebSocket {
+    constructor(...args: unknown[]) {
+      // @ts-expect-error Args will fit
+      super(...args);
+    }
+
+    public send(data: unknown) {
+      if (this.readyState !== WebSocket.OPEN)
+        fail("Shouldn't send anything through a non-OPEN socket");
+      super.send(data);
+    }
+  }
+
+  const client = createClient({
+    webSocketImpl: MockWebSocket,
+    url,
+    retryAttempts: 0,
+    onNonLazyError: noop,
+  });
+  const sub = tsubscribe(client, { query: 'subscription { ping }' });
+  await waitForOperation();
+
+  // kick the client off
+  for (const client of clients) {
+    client.close();
+    await waitForClientClose();
+  }
+
+  // dispose of the subscription which should complete the connection
+  sub.dispose();
+  await sub.waitForComplete();
+});
+
 describe('query operation', () => {
   it('should execute the query, "next" the result and then complete', async () => {
     const { url } = await startTServer();