diff --git a/src/static/js/collab_client.ts b/src/static/js/collab_client.ts
index 50271db38..bf9576b45 100644
--- a/src/static/js/collab_client.ts
+++ b/src/static/js/collab_client.ts
@@ -442,7 +442,15 @@ const getCollabClient = (ace2editor, serverVars, initialUserInfo, options, _pad)
   };
 
   const setIsPendingRevision = (value) => {
+    const wasPending = isPendingRevision;
     isPendingRevision = value;
+    // After reconnect, once all pending revisions from the server have been applied
+    // (isPendingRevision transitions from true to false), flush any unsent local changes
+    // that were queued while disconnected. The handleUserChanges() call in setChannelState
+    // (CONNECTED) is not sufficient because isPendingRevision is still true at that point.
+    if (wasPending && !value) {
+      handleUserChanges();
+    }
   };
 
   const idleFuncs = [];
diff --git a/src/tests/frontend-new/specs/reconnect_flush.spec.ts b/src/tests/frontend-new/specs/reconnect_flush.spec.ts
index 39f835bd0..3516f812f 100644
--- a/src/tests/frontend-new/specs/reconnect_flush.spec.ts
+++ b/src/tests/frontend-new/specs/reconnect_flush.spec.ts
@@ -33,12 +33,61 @@ test.describe('Pending changeset flush after reconnect', function () {
     // Reconnect User 1 by going back online.
     await page1.context().setOffline(false);
 
-    // The fix ensures handleUserChanges() is called in setUpSocket() after
-    // reconnection, so pending changes should be flushed automatically.
+    // The fix ensures handleUserChanges() is called when setIsPendingRevision
+    // transitions from true to false after reconnection, so pending changes
+    // should be flushed automatically.
     // Verify User 2 receives the offline edit.
     await expect(body2.locator('div').first()).toHaveText('initial text and offline edit');
 
     await context1.close();
     await context2.close();
   });
+
+  test('bug #5108 regression: handleUserChanges is called when isPendingRevision clears', async function ({page}) {
+    // This test verifies the specific codepath: after reconnect, when the server
+    // finishes sending CLIENT_RECONNECT messages and setIsPendingRevision(false) is
+    // called, handleUserChanges() must be triggered to flush locally-queued edits.
+    //
+    // The bug was that setChannelState('CONNECTED') fires handleUserChanges() but at
+    // that point isPendingRevision is still true, so the changes are not sent. Only
+    // after all CLIENT_RECONNECT messages arrive does isPendingRevision become false,
+    // and nothing was calling handleUserChanges() at that point.
+
+    const padId = await goToNewPad(page);
+    await clearPadContent(page);
+    await writeToPad(page, 'initial content');
+
+    const body = await getPadBody(page);
+    await expect(body.locator('div').first()).toHaveText('initial content');
+
+    // Step 1: Simulate the reconnecting state (as pad.ts socketReconnecting does).
+    await page.evaluate(() => {
+      const pad = (window as any).pad;
+      pad.collabClient.setStateIdle();
+      pad.collabClient.setIsPendingRevision(true);
+      pad.collabClient.setChannelState('RECONNECTING');
+    });
+
+    // Step 2: Type text while in "reconnecting" state (locally queued, not sent).
+    await page.keyboard.down('Control');
+    await page.keyboard.press('End');
+    await page.keyboard.up('Control');
+    await page.keyboard.press('Enter');
+    await page.keyboard.type('typed during reconnect');
+
+    // Step 3: Simulate reconnect completion.
+    // First set CONNECTED (handleUserChanges fires but bails because isPendingRevision is true).
+    // Then clear isPendingRevision, which should now trigger handleUserChanges() via the fix.
+    await page.evaluate(() => {
+      const pad = (window as any).pad;
+      pad.collabClient.setChannelState('CONNECTED');
+      pad.collabClient.setIsPendingRevision(false);
+    });
+
+    // Step 4: Open a second view and verify the locally-typed text was flushed to the server.
+    const page2 = await page.context().newPage();
+    await goToPad(page2, padId);
+    const body2 = await getPadBody(page2);
+    await expect(body2.locator('div').nth(1)).toHaveText('typed during reconnect', {timeout: 10000});
+  });
 });