diff --git a/checkov/terraform/checks/resource/aws/NeptuneClusterBackupRetention.py b/checkov/terraform/checks/resource/aws/NeptuneClusterBackupRetention.py
index 8adaf9a10d8..87f2424d571 100644
--- a/checkov/terraform/checks/resource/aws/NeptuneClusterBackupRetention.py
+++ b/checkov/terraform/checks/resource/aws/NeptuneClusterBackupRetention.py
@@ -17,7 +17,7 @@ def scan_resource_conf(self, conf):
         return CheckResult.FAILED
 
     def get_evaluated_keys(self):
-        return 'backup_retention_period'
+        return ['backup_retention_period']
 
 
 check = NeptuneClusterBackupRetention()