diff --git a/.github/workflows/e2e.yaml b/.github/workflows/e2e.yaml
index 4cda4d9..cae592f 100644
--- a/.github/workflows/e2e.yaml
+++ b/.github/workflows/e2e.yaml
@@ -10,6 +10,14 @@ on:
 permissions:
   contents: read
 
+# Only one E2E run at a time: the shared E2E_RELEASE (headlamp-e2e) in
+# privilegedescalation-dev cannot be shared across concurrent runs.
+# cancel-in-progress: false (queue, don't cancel) — cancelling in-flight
+# runs may skip the if: always() teardown, leaving dangling cluster resources.
+concurrency:
+  group: e2e-${{ github.repository }}
+  cancel-in-progress: false
+
 env:
   E2E_NAMESPACE: privilegedescalation-dev
   E2E_RELEASE: headlamp-e2e