diff --git a/awx/main/models/ha.py b/awx/main/models/ha.py
index f7ed86cd7c..5200f99d3e 100644
--- a/awx/main/models/ha.py
+++ b/awx/main/models/ha.py
@@ -4,6 +4,7 @@
 from decimal import Decimal
 import random
 import logging
+import os
 
 from django.core.validators import MinValueValidator
 from django.db import models, connection
@@ -187,7 +188,7 @@ class Instance(HasPolicyEditsMixin, BaseModel):
         """
         vargs = dict()
         if settings.AWX_CLEANUP_PATHS:
-            vargs['file_pattern'] = '{}/{}*'.format(settings.AWX_ISOLATION_BASE_PATH, JOB_FOLDER_PREFIX % '*')
+            vargs['file_pattern'] = os.path.join(settings.AWX_ISOLATION_BASE_PATH, JOB_FOLDER_PREFIX % '*') + '*'
         vargs.update(kwargs)
         if 'exclude_strings' not in vargs and vargs.get('file_pattern'):
             active_pks = list(UnifiedJob.objects.filter(execution_node=self.hostname, status__in=('running', 'waiting')).values_list('pk', flat=True))