diff --git a/script/next-checks/next-checks.sh b/script/next-checks/next-checks.sh
index 39c9d28..4cb0d43 100755
--- a/script/next-checks/next-checks.sh
+++ b/script/next-checks/next-checks.sh
@@ -17,14 +17,19 @@
 # next tests, usually this will be main
 export GERRIT_BRANCH=${GERRIT_BRANCH:="main"}
 
+
 if [ "$IS_CONTINUOUS_INTEGRATION" == 1 ]; then
-    # git operations e.g. ${get_merge_base} rely on access to main branch,
-    # we need to access via SSH for that to work currently
+    # git operations rely on access to main branch, we need to access via SSH for that to work currently
     SSH_PARAMS="-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o PubkeyAcceptedKeyTypes=+ssh-rsa -p 29418 -i ${CI_BOT_KEY}"
     REPO_SSH_URL="ssh://${CI_BOT_USERNAME}@review.trustedfirmware.org:29418/RF-A/rusted-firmware-a"
     export GIT_SSH_COMMAND="ssh ${SSH_PARAMS}"
     git remote set-url origin ${REPO_SSH_URL}
-    git fetch origin
+    git fetch --unshallow --update-shallow origin
+    git fetch --unshallow --update-shallow origin ${GERRIT_BRANCH} ${GERRIT_REFSPEC}
+
+    export merge_base=$(git merge-base \
+      $(head -n1 .git/FETCH_HEAD | cut -f1) \
+      $(tail -n1 .git/FETCH_HEAD | cut -f1))
 fi
 
 # Find the absolute path of the scripts' top directory
@@ -32,17 +37,16 @@
 export CI_ROOT=$(pwd)
 cd -
 
-. $CI_ROOT/script/static-checks/common.sh
-
 echo
 echo "###### Rust checks ######" > "$LOG_TEST_FILENAME"
 echo >> "$LOG_TEST_FILENAME"
 
 echo "Patch series being checked:" >> "$LOG_TEST_FILENAME"
-git log --oneline $(get_merge_base)..HEAD >> "$LOG_TEST_FILENAME"
+git log --oneline ${merge_base}..HEAD >> "$LOG_TEST_FILENAME"
 echo >> "$LOG_TEST_FILENAME"
 echo "Base branch reference commit:" >> "$LOG_TEST_FILENAME"
-git log --oneline -1 $(get_merge_base) >> "$LOG_TEST_FILENAME"
+git log --oneline -1 ${merge_base} >> "$LOG_TEST_FILENAME"
+
 
 echo >> "$LOG_TEST_FILENAME"