diff --git a/.maintain/common/lib.sh b/.maintain/common/lib.sh
index e1858c20c7e..4bf22780083 100644
--- a/.maintain/common/lib.sh
+++ b/.maintain/common/lib.sh
@@ -51,9 +51,9 @@ has_client_changes() {
 # checks if the spec/impl version has increased
 check_runtime() {
   VERSIONS_FILE="$1"
-  add_spec_version="$(git diff "${LATEST_TAG_NAME}" "${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
+  add_spec_version="$(git diff "${LATEST_TAG_NAME}" "origin/${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
     sed -n -r "s/^\+[[:space:]]+spec_version: +([0-9]+),$/\1/p")"
-  sub_spec_version="$(git diff "${LATEST_TAG_NAME}" "${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
+  sub_spec_version="$(git diff "${LATEST_TAG_NAME}" "origin/${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
     sed -n -r "s/^\-[[:space:]]+spec_version: +([0-9]+),$/\1/p")"
   if [ "${add_spec_version}" != "${sub_spec_version}" ]; then
 
@@ -70,9 +70,9 @@ check_runtime() {
     # check for impl_version updates: if only the impl versions changed, we assume
     # there is no consensus-critical logic that has changed.
 
-    add_impl_version="$(git diff "${LATEST_TAG_NAME}" "${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
+    add_impl_version="$(git diff "${LATEST_TAG_NAME}" "origin/${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
       sed -n -r 's/^\+[[:space:]]+impl_version: +([0-9]+),$/\1/p')"
-    sub_impl_version="$(git diff "${LATEST_TAG_NAME}" "${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
+    sub_impl_version="$(git diff "${LATEST_TAG_NAME}" "origin/${GITHUB_REF_NAME}" -- "${VERSIONS_FILE}" |
       sed -n -r 's/^\-[[:space:]]+impl_version: +([0-9]+),$/\1/p')"
 
     # see if the impl version changed