diff --git a/.github/workflows/label-subissues.yaml b/.github/workflows/label-subissues.yaml
new file mode 100644
index 0000000..fb67e66
--- /dev/null
+++ b/.github/workflows/label-subissues.yaml
@@ -0,0 +1,35 @@
+name: Label Subissues
+on:
+  issues:
+    types: [opened, edited]
+
+jobs:
+  apply-label:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+    steps:
+      - name: Check for Parent and Label
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ISSUE_NODE_ID: ${{ github.event.issue.node_id }}
+        run: |
+          # Use GraphQL to check if this issue has a parent
+          PARENT_ID=$(gh api graphql -f query='
+            query($id: ID!) {
+              node(id: $id) {
+                ... on Issue {
+                  parent {
+                    id
+                  }
+                }
+              }
+            }' -f id=$ISSUE_NODE_ID --jq '.data.node.parent.id')
+
+          # If PARENT_ID is not null, it is a subissue
+          if [ "$PARENT_ID" != "null" ] && [ -n "$PARENT_ID" ]; then
+            echo "Subissue detected. Applying label..."
+            gh issue edit ${{ github.event.issue.number }} --add-label "subissue"
+          else
+            echo "This is a top-level issue."
+          fi