diff --git a/crates/aiken-lang/src/tipo/infer.rs b/crates/aiken-lang/src/tipo/infer.rs
index 19288ac6..6a2505e9 100644
--- a/crates/aiken-lang/src/tipo/infer.rs
+++ b/crates/aiken-lang/src/tipo/infer.rs
@@ -319,7 +319,17 @@ fn infer_definition(
                     });
                 }
 
-                let typed_params = typed_fun.arguments.drain(0..params_length).collect();
+                let typed_params = typed_fun.arguments
+                    .drain(0..params_length)
+                    .map(|mut arg| {
+                        if arg.tipo.is_unbound() {
+                            arg.tipo = builtins::data();
+                        }
+
+                        arg
+                    })
+                    .collect();
+
 
                 if typed_fun.arguments.len() < 2 || typed_fun.arguments.len() > 3 {
                     return Err(Error::IncorrectValidatorArity {
@@ -328,6 +338,12 @@ fn infer_definition(
                     });
                 }
 
+                for arg in typed_fun.arguments.iter_mut() {
+                    if arg.tipo.is_unbound() {
+                        arg.tipo = builtins::data();
+                    }
+                }
+
                 let typed_other_fun = other_fun
                     .map(|mut other| -> Result<TypedFunction, Error> {
                         let params = params.into_iter().chain(other.arguments);
@@ -372,10 +388,18 @@ fn infer_definition(
                             });
                         }
 
+                        for arg in other_typed_fun.arguments.iter_mut() {
+                            if arg.tipo.is_unbound() {
+                                arg.tipo = builtins::data();
+                            }
+                        }
+
                         Ok(other_typed_fun)
                     })
                     .transpose();
 
+
+
                 Ok(Definition::Validator(Validator {
                     doc,
                     end_position,