diff --git a/src/evaluate/mod.rs b/src/evaluate/mod.rs
index 09355b5..4e5cca9 100644
--- a/src/evaluate/mod.rs
+++ b/src/evaluate/mod.rs
@@ -1,10 +1,10 @@
 mod operator;
 mod function;
-mod constant;
 mod evaluate;
 
 pub use self::evaluate::evaluate;
 
+#[derive(Debug)]
 pub enum EvalError {
 	BadMath,
 	TooBig,