diff --git a/jenkins/userid-validation b/jenkins/userid-validation
index d358760..c8ae4a9 100755
--- a/jenkins/userid-validation
+++ b/jenkins/userid-validation
@@ -48,6 +48,19 @@
     "${GERRIT_CHANGE_NUMBER},${GERRIT_PATCHSET_NUMBER}" \
     --ok-to-test=0 -t autogenerated:jenkins --notify=NONE
 
+# Add reviewers based on OWNERS files.
+"${WORKSPACE}/openbmc-build-scripts/tools/owners" -p "${WORKSPACE}" reviewers |
+{
+    while read -r reviewer ;
+    do
+        # shellcheck disable=2086 # GERRIT_COMMAND is purposefully wordsplit.
+        ${GERRIT_COMMAND}/a/changes/${GERRIT_PROJECT/\//%2F}~${GERRIT_BRANCH}~${GERRIT_CHANGE_ID}/reviewers \
+            -X POST \
+            -H "Content-Type: application/json" \
+            -d "$reviewer" || true
+    done
+} || true
+
 # Write full list of users to a file
 GERRIT_CI_GROUPS=( \
     alibaba/ci-authorized \
diff --git a/tools/owners b/tools/owners
index acae840..d35fe5f 100755
--- a/tools/owners
+++ b/tools/owners
@@ -68,7 +68,7 @@
         self.owners: Set[str] = set(owners.get("owners") or [])
         self.reviewers: Set[str] = set(owners.get("reviewers") or [])
 
-        for e in owners.get("matchers", []):
+        for e in owners.get("matchers", None) or []:
             if "exact" in e:
                 self.__exact(files, e)
             elif "partial_regex" in e:
@@ -140,7 +140,8 @@
     )
     parser_reviewers.add_argument(
         "--push-args",
-        action=argparse.BooleanOptionalAction,
+        default=False,
+        action='store_true',
         help="Format as git push options",
     )
     parser_reviewers.add_argument(