diff --git a/optimizely/event_builder.py b/optimizely/event_builder.py
index 2580d791..00b2c31d 100644
--- a/optimizely/event_builder.py
+++ b/optimizely/event_builder.py
@@ -215,7 +215,7 @@ def _add_required_params_for_conversion(self, event_key, event_tags, decisions):
 
       self.params[self.EventParams.EVENT_METRICS] = event_values
 
-      for event_tag_id in event_tags.keys():
+      for event_tag_id in sorted(event_tags.keys()):
         event_tag_value = event_tags.get(event_tag_id)
         if event_tag_value is None:
           continue
diff --git a/tests/test_optimizely.py b/tests/test_optimizely.py
index db63c2b4..4c97c5b1 100644
--- a/tests/test_optimizely.py
+++ b/tests/test_optimizely.py
@@ -743,14 +743,14 @@ def test_track__with_invalid_event_tags(self):
       'eventEntityId': '111095',
       'eventName': 'test_event',
       'eventFeatures': [{
-        'name': 'value',
+        'name': 'revenue',
         'type': 'custom',
-        'value': '1.234',
+        'value': '4200',
         'shouldIndex': False,
       }, {
-        'name': 'revenue',
+        'name': 'value',
         'type': 'custom',
-        'value': '4200',
+        'value': '1.234',
         'shouldIndex': False,
       }],
       'eventMetrics': [],