diff --git a/.gitea/workflows/gate-check-v3.yml b/.gitea/workflows/gate-check-v3.yml
index 27aba8798..fc0cbf271 100644
--- a/.gitea/workflows/gate-check-v3.yml
+++ b/.gitea/workflows/gate-check-v3.yml
@@ -32,6 +32,12 @@ on:
   # iterating all open PRs when PR_NUMBER is empty.
   workflow_dispatch:
 
+# Cancel stale runs so the 8-runner pool stays available for PR jobs.
+# Per-SHA group ensures push and cron runs at different SHAs don't cancel each other.
+concurrency:
+  group: gate-check-v3-${{ github.event.pull_request.head.sha || github.sha }}
+  cancel-in-progress: true
+
 permissions:
   # read: contents — for checkout (base ref, not PR head for security)
   # read: pull-requests — for reading PR info via API
diff --git a/.gitea/workflows/secret-pattern-drift.yml b/.gitea/workflows/secret-pattern-drift.yml
index 879341ae4..1f8672ad2 100644
--- a/.gitea/workflows/secret-pattern-drift.yml
+++ b/.gitea/workflows/secret-pattern-drift.yml
@@ -44,6 +44,12 @@ on:
       - ".github/scripts/lint_secret_pattern_drift.py"
       - ".githooks/pre-commit"
 
+# Cancel stale runs to keep the 8-runner pool available for PR jobs.
+# Per-SHA group ensures push and scheduled runs at different SHAs don't cancel each other.
+concurrency:
+  group: secret-pattern-drift-${{ github.event.pull_request.head.sha || github.sha }}
+  cancel-in-progress: true
+
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
 
diff --git a/.gitea/workflows/weekly-platform-go.yml b/.gitea/workflows/weekly-platform-go.yml
index 6bf9e199b..af81113f1 100644
--- a/.gitea/workflows/weekly-platform-go.yml
+++ b/.gitea/workflows/weekly-platform-go.yml
@@ -22,6 +22,11 @@ on:
     - cron: '17 4 * * 1'  # Mondays at 04:17 UTC
   workflow_dispatch:
 
+# Cancel stale runs to keep the 8-runner pool available for PR jobs.
+concurrency:
+  group: weekly-platform-go-${{ github.event.pull_request.head.sha || github.sha }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
   statuses: write