diff --git a/.github/workflows/release-plugin.yml b/.github/workflows/release-plugin.yml
index b0aadecf..281ff2d0 100644
--- a/.github/workflows/release-plugin.yml
+++ b/.github/workflows/release-plugin.yml
@@ -37,6 +37,11 @@ jobs:
     name: Open the ${{ matrix.plugin }} catalog PR
     needs: [release-plugin]
     runs-on: ubuntu-latest
+    # Every release of a plugin updates the same open catalog PR, so two
+    # releases close together must not write its branch at once.
+    concurrency:
+      group: plugin-index-datum-cloud-datumctl-plugins-${{ matrix.plugin }}-main
+      cancel-in-progress: false
     permissions:
       contents: read
     strategy:
@@ -53,7 +58,7 @@ jobs:
           repositories: datumctl-plugins
 
       - name: Update the ${{ matrix.plugin }} plugin manifest
-        uses: datum-cloud/actions/update-plugin-index@v1.21.0
+        uses: datum-cloud/actions/update-plugin-index@v1.22.0
         with:
           index-repo: datum-cloud/datumctl-plugins
           plugin-name: ${{ matrix.plugin }}