diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 6cdf60449..cfe3db7d0 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -27,8 +27,12 @@ concurrency:
   # run, and any other label change has no effect. Note such an event still
   # creates a run of this workflow, which is skipped, and would then hide the
   # one in progress on the pull request. 'pr-run-cleanup.yml' deletes those.
+  # Key pull request runs on the number: 'github.ref' is the base branch once
+  # the pull request is closed, so unlabel events would cancel base runs.
   group: >-
-    ${{ github.workflow }}-${{ github.ref }}-${{
+    ${{ github.workflow }}-${{
+    github.event_name == 'pull_request'
+    && format('pr-{0}', github.event.number) || github.ref }}-${{
     (github.event.action == 'labeled' || github.event.action == 'unlabeled')
     && github.event.label.name != 'pr: dev-coverage'
     && github.run_id || 'shared' }}
diff --git a/.github/workflows/regression.yml b/.github/workflows/regression.yml
index 2941e00af..eee530fa9 100644
--- a/.github/workflows/regression.yml
+++ b/.github/workflows/regression.yml
@@ -30,8 +30,12 @@ concurrency:
   # run, and any other label change has no effect. Note such an event still
   # creates a run of this workflow, which is skipped, and would then hide the
   # one in progress on the pull request. 'pr-run-cleanup.yml' deletes those.
+  # Key pull request runs on the number: 'github.ref' is the base branch once
+  # the pull request is closed, so unlabel events would cancel base runs.
   group: >-
-    ${{ github.workflow }}-${{ github.ref }}-${{
+    ${{ github.workflow }}-${{
+    github.event_name == 'pull_request'
+    && format('pr-{0}', github.event.number) || github.ref }}-${{
     (github.event.action == 'labeled' || github.event.action == 'unlabeled')
     && github.event.label.name != 'pr: regression'
     && github.run_id || 'shared' }}
diff --git a/.github/workflows/rtlmeter.yml b/.github/workflows/rtlmeter.yml
index c0be3de49..3a49b2c0f 100644
--- a/.github/workflows/rtlmeter.yml
+++ b/.github/workflows/rtlmeter.yml
@@ -29,8 +29,12 @@ concurrency:
   # run, and any other label change has no effect. Note such an event still
   # creates a run of this workflow, which is skipped, and would then hide the
   # one in progress on the pull request. 'pr-run-cleanup.yml' deletes those.
+  # Key pull request runs on the number: 'github.ref' is the base branch once
+  # the pull request is closed, so unlabel events would cancel base runs.
   group: >-
-    ${{ github.workflow }}-${{ github.ref }}-${{
+    ${{ github.workflow }}-${{
+    github.event_name == 'pull_request'
+    && format('pr-{0}', github.event.number) || github.ref }}-${{
     (github.event.action == 'labeled' || github.event.action == 'unlabeled')
     && github.event.label.name != 'pr: rtlmeter'
     && github.run_id || 'shared' }}