diff --git a/.github/workflows/preview-comment.yml b/.github/workflows/preview-comment.yml
index 36303c3..3a788b0 100644
--- a/.github/workflows/preview-comment.yml
+++ b/.github/workflows/preview-comment.yml
@@ -2,7 +2,7 @@
 name: Pull Request Comments
 
 on:
-    pull_request:
+    pull_request_target:
 
 # Disable permissions for all available scopes by default.
 # Any needed permissions should be configured at the job level.
diff --git a/validate_pr.py b/validate_pr.py
index ca298b7..510de88 100644
--- a/validate_pr.py
+++ b/validate_pr.py
@@ -85,8 +85,9 @@ def find_urls(obj):
         
 
 def get_touched_directories():
-    # Run git diff command to get the list of directories touched in the current branch
-    diff_output = os.popen('git diff --name-only origin/trunk').read()
+    # Run git diff command to get the list of directories touched in the current branch as compared to 
+    # the point where it was forked from the trunk branch
+    diff_output = os.popen('git diff --name-only $(git merge-base trunk HEAD)').read()
     touched_dirs = set()
 
     # Extract the directory paths from the diff output