1 files changed, 4 insertions, 0 deletions
diff --git a/src/error.rs b/src/error.rs
index d8d4664..b489cd1 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -11,6 +11,7 @@ use crate::vm::{Op, Value};
 #[derive(Debug, Clone)]
 pub enum ErrorKind {
     TypeError(Op, Vec<Type>),
+    ExternTypeMismatch(String, Vec<Type>),
     RuntimeTypeError(Op, Vec<Value>),
     Assert,
     InvalidProgram,
@@ -36,6 +37,9 @@ impl fmt::Display for ErrorKind {
                     .fold(String::new(), |a, v| { format!("{}{:?}, ", a, v) });
                 write!(f, "{} Cannot apply {:?} to types {}", "Type Error".bold(), op, types)
             }
+            ErrorKind::ExternTypeMismatch(name, types) => {
+                write!(f, "{} Extern function '{}' doesn't accept argument(s) with type(s) {:?}", "Type Error".bold(), name, types)
+            }
             ErrorKind::RuntimeTypeError(op, values) => {
                 let values = values
                     .iter()