diff --git a/Jenkinsfile.pjt b/Jenkinsfile.pjt
index f1a5480..0b95d38 100644
--- a/Jenkinsfile.pjt
+++ b/Jenkinsfile.pjt
@@ -238,7 +238,9 @@ pipeline {
             echo "[1/2] docker registry login"
             echo "$DOCKER_PASS" | docker login ${REGISTRY_HOST} -u "$DOCKER_USER" --password-stdin
 
-            curl -u "$DOCKER_USER":"$DOCKER_PASS" https://${REGISTRY_HOST}/v2/${IMAGE_REPO}/tags/list
+            TAGS_TO_DELETE=$(curl -s -u "$DOCKER_USER:$DOCKER_PASS" https://${REGISTRY_HOST}/v2/${IMAGE_REPO}/tags/list | sed -n 's/.*"tags":\[\(.*\)\].*/\1/p' | tr -d '"' | tr ',' '\n' | grep -E '^[0-9]+' | sort -t- -k1,1n | head -n -5)
+
+            echo "$TAGS_TO_DELETE"
 
             docker logout ${REGISTRY_HOST}
           '''