diff --git a/mis_builder/models/mis_builder.py b/mis_builder/models/mis_builder.py
index 7278e495..b31feb7b 100644
--- a/mis_builder/models/mis_builder.py
+++ b/mis_builder/models/mis_builder.py
@@ -60,7 +60,7 @@ def _utc_midnight(d, tz_name, add_day=0):
 
 
 def _clean(varStr):
-    return re.sub('\W|^(?=\d)', '_', varStr)
+    return re.sub('\W|^(?=\d)', '_', varStr).lower()
 
 
 class mis_report_kpi(orm.Model):