diff --git a/schala-lang/language/src/builtin.rs b/schala-lang/language/src/builtin.rs
index f44848f..2d8c080 100644
--- a/schala-lang/language/src/builtin.rs
+++ b/schala-lang/language/src/builtin.rs
@@ -35,7 +35,33 @@ pub enum Builtin {
 
 impl Builtin {
   pub fn get_type(&self) -> Type {
-    ty!(Nat -> Nat -> Nat)
+    use Builtin::*;
+    match self {
+      Add => ty!(Nat -> Nat -> Nat),
+      Subtract => ty!(Nat -> Nat -> Nat),
+      Multiply => ty!(Nat -> Nat -> Nat),
+      Divide => ty!(Nat -> Nat -> Float),
+      Quotient => ty!(Nat -> Nat -> Nat),
+      Modulo => ty!(Nat -> Nat -> Nat),
+      Exponentiation => ty!(Nat -> Nat -> Nat),
+      BitwiseAnd => ty!(Nat -> Nat -> Nat),
+      BitwiseOr => ty!(Nat -> Nat -> Nat),
+      BooleanAnd => ty!(Bool -> Bool -> Bool),
+      BooleanOr => ty!(Bool -> Bool -> Bool),
+      BooleanNot => ty!(Bool -> Bool),
+      Equality => ty!(Nat -> Nat -> Bool),
+      LessThan => ty!(Nat -> Nat -> Bool),
+      LessThanOrEqual => ty!(Nat -> Nat -> Bool),
+      GreaterThan => ty!(Nat -> Nat -> Bool),
+      GreaterThanOrEqual => ty!(Nat -> Nat -> Bool),
+      Comparison => ty!(Nat -> Nat -> Ordering),
+      FieldAccess => ty!(Unit),
+      IOPrint => ty!(Unit),
+      IOPrintLn => ty!(Unit) ,
+      IOGetLine => ty!(StringT),
+      Assignment => ty!(Unit),
+      Concatenate => ty!(StringT -> StringT -> StringT),
+    }
   }
 }