diff --git a/packages/lexical-react/src/shared/useYjsCollaboration.tsx b/packages/lexical-react/src/shared/useYjsCollaboration.tsx
index 371a6f4721f..a8f4e49da17 100644
--- a/packages/lexical-react/src/shared/useYjsCollaboration.tsx
+++ b/packages/lexical-react/src/shared/useYjsCollaboration.tsx
@@ -155,9 +155,18 @@ export function useYjsCollaboration(
 
     return () => {
       if (isReloadingDoc.current === false) {
-        Promise.resolve(connectionPromise).then(() => {
+        if (connectionPromise) {
+          connectionPromise.then(disconnect);
+        } else {
+          // Workaround for race condition in StrictMode. It's possible there
+          // is a different race for the above case where connect returns a
+          // promise, but we don't have an example of that in-repo.
+          // It's possible that there is a similar issue with
+          // TOGGLE_CONNECT_COMMAND below when the provider connect returns a
+          // promise.
+          // https://github.com/facebook/lexical/issues/6640
           disconnect();
-        });
+        }
       }
 
       provider.off('sync', onSync);
@@ -198,18 +207,16 @@ export function useYjsCollaboration(
     return editor.registerCommand(
       TOGGLE_CONNECT_COMMAND,
       (payload) => {
-        if (connect !== undefined && disconnect !== undefined) {
-          const shouldConnect = payload;
-
-          if (shouldConnect) {
-            // eslint-disable-next-line no-console
-            console.log('Collaboration connected!');
-            connect();
-          } else {
-            // eslint-disable-next-line no-console
-            console.log('Collaboration disconnected!');
-            disconnect();
-          }
+        const shouldConnect = payload;
+
+        if (shouldConnect) {
+          // eslint-disable-next-line no-console
+          console.log('Collaboration connected!');
+          connect();
+        } else {
+          // eslint-disable-next-line no-console
+          console.log('Collaboration disconnected!');
+          disconnect();
         }
 
         return true;