diff --git a/config/unscaleable_units.yml b/config/unscaleable_units.yml
index 843928830c..75620669c7 100644
--- a/config/unscaleable_units.yml
+++ b/config/unscaleable_units.yml
@@ -14,3 +14,4 @@
 - "kg/GJ"
 - "kg/MWh"
 - "MWoutput"
+- "enum"