1 files changed, 2 insertions, 0 deletions

diff --git a/src/lisp/error.rs b/src/lisp/error.rs
index b90e211..a360eb2 100644
--- a/src/lisp/error.rs
+++ b/src/lisp/error.rs
@@ -90,6 +90,7 @@ pub enum EvalError {
     DivByZero,
     TypeMismatch,
     NoFileName,
+    CustomInternal(&'static str),
 }
 
 impl fmt::Display for EvalError {
@@ -112,6 +113,7 @@ impl fmt::Display for EvalError {
             Self::TypeMismatch => write!(f, "mismatched types"),
             Self::DivByZero => write!(f, "attempt to divide by zero"),
             Self::NoFileName => write!(f, "no file name specified"),
+            Self::CustomInternal(s) => write!(f, "{}", s),
         }
     }
 }