diff --git a/defaults/main.yml b/defaults/main.yml
index be18b32..12fcc6e 100755
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -8,5 +8,8 @@ rc_version: 4.8.1
 # WIP to get to 5.0
 mongo_version: 4.4
 
+# WIP to get to 5.0 - if same as mongo_version or false, feature compatibility version will not be set
+prev_mongo_version: 4.2
+
 # backup by default - saves to /home/{{ main_user }}/rocketchat/data/dump/2015-07-09T16:59:26Z" (iso8601 of current date)
 backup_db: true
\ No newline at end of file
diff --git a/tasks/rocketchat.yml b/tasks/rocketchat.yml
index 43605f4..063e777 100644
--- a/tasks/rocketchat.yml
+++ b/tasks/rocketchat.yml
@@ -122,9 +122,22 @@
     dest: "{{ local_backup_dir }}"
   tags: mongodump
 
+- name: Set feature compability version if we are upgrading mongoDB
+  when: prev_mongo_version and prev_mongo_version != mongo_version
+  community.docker.docker_container_exec:
+    container: rocketchat_mongo_1
+    command: >
+      bash -c 'mongo --eval "db.adminCommand( { setFeatureCompatibilityVersion: \"{{ prev_mongo_version }}\" } )"'
+  #    chdir: /home/{{ main_user }}/rocketchat
+  #    chdir: /
+  #docker-compose exec mongo
+  register: __set_feature_compability_version_mongo
+  tags: mongoupgrade
+
 - name: debug docker compose down
   debug:
     var: __remove_rocketchat
+  tags: bring-down
 
 - name: debug docker compose up debug
   debug:
@@ -135,3 +148,10 @@
   debug:
     var: __backup_result
   tags: mongodump
+
+
+- name: debug mongo upgrade set feature compatability version
+  when: prev_mongo_version and prev_mongo_version != mongo_version
+  debug:
+    var: __set_feature_compability_version_mongo
+  tags: mongoupgrade
\ No newline at end of file