diff --git a/scripts/build-unit-test-docker b/scripts/build-unit-test-docker
index 7bc1157..e3650ab 100755
--- a/scripts/build-unit-test-docker
+++ b/scripts/build-unit-test-docker
@@ -21,6 +21,7 @@
 #                     Default: "", proxy is not setup if this is not set
 
 import os
+import re
 import sys
 import threading
 from datetime import date
@@ -433,8 +434,9 @@
         #   This section is locked because we are modifying the PackageDef.
         Package.lock.acquire()
         for line in lookup.split("\n"):
-            if f"refs/heads/{branch}" in line:
+            if re.fullmatch(f".*{branch}$", line.strip()):
                 self.pkg_def["rev"] = line.split()[0]
+                break
             elif (
                 "refs/heads/master" in line or "refs/heads/main" in line
             ) and "rev" not in self.pkg_def: