diff --git a/extensions/memory-core/src/memory/manager-sync-control.ts b/extensions/memory-core/src/memory/manager-sync-control.ts
index 96c9db939ab..0595a263248 100644
--- a/extensions/memory-core/src/memory/manager-sync-control.ts
+++ b/extensions/memory-core/src/memory/manager-sync-control.ts
@@ -102,11 +102,12 @@ export async function runMemorySyncWithReadonlyRecovery(
     try {
       state.db.close();
     } catch {}
+    const previousVectorDims = state.vector.dims;
     state.db = state.openDatabase();
     state.resetVectorState();
     state.ensureSchema();
     const meta = state.readMeta();
-    state.vector.dims = meta?.vectorDims;
+    state.vector.dims = meta?.vectorDims ?? previousVectorDims;
     try {
       await state.runSync(params);
       state.readonlyRecoverySuccesses += 1;
diff --git a/extensions/memory-core/src/memory/manager.readonly-recovery.test.ts b/extensions/memory-core/src/memory/manager.readonly-recovery.test.ts
index 067ce7cadae..5e149754686 100644
--- a/extensions/memory-core/src/memory/manager.readonly-recovery.test.ts
+++ b/extensions/memory-core/src/memory/manager.readonly-recovery.test.ts
@@ -136,6 +136,7 @@ describe("memory manager readonly recovery", () => {
     expect(harness.runSync).toHaveBeenCalledTimes(2);
     expect(harness.openDatabase).toHaveBeenCalledTimes(1);
     expect(harness.resetVectorState).toHaveBeenCalledTimes(1);
+    expect(harness.vector.dims).toBe(123);
     expect(initialClose).toHaveBeenCalledTimes(1);
     expectReadonlyRecoveryStatus(harness, params.expectedLastError);
   }
@@ -194,6 +195,20 @@ describe("memory manager readonly recovery", () => {
     expect(harness.vectorDegradedWriteWarningShown).toBe(false);
   });
 
+  it("prefers reopened vector dims when metadata is available", async () => {
+    const { harness } = createReadonlyRecoveryHarness();
+    harness.readMeta.mockReturnValueOnce({ vectorDims: 768 });
+    harness.runSync.mockRejectedValueOnce(new Error("attempt to write a readonly database"));
+
+    await expect(
+      runSyncWithReadonlyRecovery(harness, {
+        reason: "test",
+      }),
+    ).resolves.toBeUndefined();
+
+    expect(harness.vector.dims).toBe(768);
+  });
+
   it("sets busy_timeout on memory sqlite connections", async () => {
     const db = openMemoryDatabaseAtPath(indexPath, false);
     const row = db.prepare("PRAGMA busy_timeout").get() as