diff --git a/schala-lang/language/src/typechecking.rs b/schala-lang/language/src/typechecking.rs
index 01f39c1..4ae4fca 100644
--- a/schala-lang/language/src/typechecking.rs
+++ b/schala-lang/language/src/typechecking.rs
@@ -30,13 +30,17 @@ impl TypeError {
 #[derive(Debug, Clone, PartialEq)]
 pub enum Type {
   Const(TypeConst),
+  Var(TypeVar),
   Arrow(Box<Type>, Box<Type>),
   Compound {
-    ty: Box<Type>, 
+    ty_name: String,
     args:Vec<Type>
   }
 }
 
+#[derive(Debug, Clone, PartialEq)]
+pub struct TypeVar(String);
+
 #[derive(Debug, Clone, PartialEq)]
 pub enum TypeConst {
   Unit,