diff --git a/.github/workflows/plugin-prerelease.yml b/.github/workflows/plugin-prerelease.yml
index 1be499ae7781..2b0a8507bdeb 100644
--- a/.github/workflows/plugin-prerelease.yml
+++ b/.github/workflows/plugin-prerelease.yml
@@ -341,7 +341,7 @@ jobs:
       - name: Run extension shard
         env:
           NODE_OPTIONS: --max-old-space-size=8192
-          OPENCLAW_EXTENSION_BATCH_PARALLEL: 2
+          OPENCLAW_EXTENSION_BATCH_PARALLEL: 1
           OPENCLAW_VITEST_MAX_WORKERS: 1
           OPENCLAW_EXTENSION_BATCH: ${{ matrix.extensions_csv }}
         run: pnpm test:extensions:batch "$OPENCLAW_EXTENSION_BATCH"