diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 3c3fcf41b6..a3d8d43306 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -4811,7 +4811,7 @@ class InstanceGroupSerializer(BaseSerializer):
         return value
 
     def validate_policy_instance_minimum(self, value):
-        if value and self.instance self.instance.is_containerized:
+        if value and self.instance and self.instance.is_containerized:
             raise serializers.ValidationError(_('Containerized instances may not be managed via the API'))
         return value