diff --git a/docker/web/celery/worker/run.sh b/docker/web/celery/worker/run.sh
index 79b53d9a1..72e6d0a7e 100755
--- a/docker/web/celery/worker/run.sh
+++ b/docker/web/celery/worker/run.sh
@@ -2,7 +2,8 @@
 
 set -euo pipefail
 
-TASK_CONCURRENCY=${CELERYD_CONCURRENCY:-15000}
+TASK_CONCURRENCY=${CELERYD_CONCURRENCY:-5000}
+PREFETCH_MULTIPLIER=${CELERYD_PREFETCH_MULTIPLIER:-2}  # Default is 4
 
 # DEBUG set in .env_docker_compose
 if [ ${DEBUG:-0} = 1 ]; then
@@ -30,6 +31,7 @@ exec celery --no-color -A config.celery_app worker \
      --pool=gevent \
      --loglevel $log_level \
      --concurrency="${TASK_CONCURRENCY}" \
+     --prefetch-multiplier="${PREFETCH_MULTIPLIER}" \
      --without-heartbeat \
      --without-gossip \
      --without-mingle -E -Q "$WORKER_QUEUES"
diff --git a/safe_transaction_service/history/tasks.py b/safe_transaction_service/history/tasks.py
index 9181afd28..ecfea2cf8 100644
--- a/safe_transaction_service/history/tasks.py
+++ b/safe_transaction_service/history/tasks.py
@@ -258,10 +258,10 @@ def process_decoded_internal_txs_task(self) -> Optional[int]:
                         safe_to_process
                     ).not_processed().update(processed=True)
                 else:
-                    count += 1
                     process_decoded_internal_txs_for_safe_task.delay(
                         safe_to_process, reindex_master_copies=True
                     )
+                    count += 1
 
             if not count:
                 logger.info("No Safes to process")
diff --git a/safe_transaction_service/utils/tasks.py b/safe_transaction_service/utils/tasks.py
index df88d1ea9..811dd6ea1 100644
--- a/safe_transaction_service/utils/tasks.py
+++ b/safe_transaction_service/utils/tasks.py
@@ -52,6 +52,13 @@ def shutdown_worker():
         logger.warning("No redis locks to release")
 
 
+def get_task_lock_name(task_name: str, lock_name_suffix: Optional[str] = None) -> str:
+    lock_name = f"locks:tasks:{task_name}"
+    if lock_name_suffix:
+        lock_name += f":{lock_name_suffix}"
+    return lock_name
+
+
 @contextlib.contextmanager
 def only_one_running_task(
     task: CeleryTask,
@@ -74,9 +81,7 @@ def only_one_running_task(
     if WORKER_STOPPED:
         raise LockError("Worker is stopping")
     redis = get_redis()
-    lock_name = f"locks:tasks:{task.name}"
-    if lock_name_suffix:
-        lock_name += f":{lock_name_suffix}"
+    lock_name = get_task_lock_name(task.name, lock_name_suffix=lock_name_suffix)
     with redis.lock(lock_name, blocking=False, timeout=lock_timeout) as lock:
         try:
             ACTIVE_LOCKS.add(lock_name)