diff --git a/tools/find-changed-builds.py b/tools/find-changed-builds.py
index 731ebd6f1e..af80bb9d82 100755
--- a/tools/find-changed-builds.py
+++ b/tools/find-changed-builds.py
@@ -10,11 +10,14 @@ from colorama import Fore, Style
 changed = set(os.getenv('CHANGED').split(' '))
 changed.discard('')
 
+target_ref = os.getenv('TARGET_REF')
+source_ref = os.getenv('SOURCE_REF')
+
 for appid in sorted(changed):
-    metadata_file = 'metadata/%s.yml' % appid
+    metadata_file = f'metadata/{appid}.yml'
     diff = subprocess.check_output(
         (
-            'git diff --no-color --diff-filter=d HEAD^...HEAD -- ' + metadata_file
+            f'git diff --no-color --diff-filter=d {target_ref}...{source_ref} -- {metadata_file}' 
         ).split(' ')
     )
 
@@ -71,7 +74,7 @@ for appid in sorted(changed):
     signatures_dir = 'metadata/%s/signatures/' % appid
     diff = subprocess.check_output(
         (
-            'git diff --name-only --no-color --diff-filter=d FETCH_HEAD...HEAD -- '
+            f'git diff --name-only --no-color --diff-filter=d {target_ref}...{source_ref} -- '
             + signatures_dir
         ).split(' ')
     )