diff --git a/calc.js b/calc.js
index 26dd802..87332d2 100644
--- a/calc.js
+++ b/calc.js
@@ -1,5 +1,6 @@
 import {
   calculate,
+  toID,
   Field,
   Generations,
   Move,
@@ -266,11 +267,11 @@ function parseAndCalculate(line) {
   }
 
   // Pre-checking before the calculator throws unreadable errors.
-  if (!gen.species.get(attacker.toLowerCase()))
+  if (!gen.species.get(toID(attacker)))
     throw Error(`No species named ${attacker}`);
-  if (!gen.species.get(defender.toLowerCase()))
+  if (!gen.species.get(toID(defender)))
     throw Error(`No species named ${defender}`);
-  if (!gen.moves.get(move.toLowerCase())) throw Error(`No move named ${move}`);
+  if (!gen.moves.get(toID(move))) throw Error(`No move named ${move}`);
 
   return calculate(
     gen,