diff --git a/.github/workflows/flowzone.yml b/.github/workflows/flowzone.yml
index e33c954..d426f3b 100644
--- a/.github/workflows/flowzone.yml
+++ b/.github/workflows/flowzone.yml
@@ -18,4 +18,13 @@ jobs:
   flowzone:
     name: Flowzone
     uses: product-os/flowzone/.github/workflows/flowzone.yml@master
+    # prevent duplicate workflow executions for pull_request and pull_request_target
+    if: |
+      (
+        github.event.pull_request.head.repo.full_name == github.repository &&
+        github.event_name == 'pull_request'
+      ) || (
+        github.event.pull_request.head.repo.full_name != github.repository &&
+        github.event_name == 'pull_request_target'
+      )
     secrets: inherit