diff --git a/dust-lang/src/abstract_tree/type.rs b/dust-lang/src/abstract_tree/type.rs
index 7301b6d..3ec4b66 100644
--- a/dust-lang/src/abstract_tree/type.rs
+++ b/dust-lang/src/abstract_tree/type.rs
@@ -18,7 +18,7 @@ pub enum Type {
     Float,
     Function {
         type_parameters: Option<Vec<Identifier>>,
-        value_parameters: Vec<(Identifier, Type)>,
+        value_parameters: Vec<Type>,
         return_type: Box<Type>,
     },
     Generic(Option<Box<Type>>),
@@ -236,8 +236,8 @@ impl Display for Type {
                     write!(f, ")(")?;
                 }
 
-                for (identifier, r#type) in value_parameters {
-                    write!(f, "{identifier}: {type}")?;
+                for r#type in value_parameters {
+                    write!(f, "{type}")?;
                 }
 
                 write!(f, ") : {}", return_type)
diff --git a/dust-lang/src/abstract_tree/type_constructor.rs b/dust-lang/src/abstract_tree/type_constructor.rs
index 013c2ff..fde1174 100644
--- a/dust-lang/src/abstract_tree/type_constructor.rs
+++ b/dust-lang/src/abstract_tree/type_constructor.rs
@@ -49,7 +49,35 @@ impl TypeConstructor {
 
     pub fn construct(self, context: &Context) -> Result<Type, ValidationError> {
         let r#type = match self {
-            TypeConstructor::Function(_) => todo!(),
+            TypeConstructor::Function(function_type_constructor) => {
+                let FunctionTypeConstructor {
+                    type_parameters: declared_type_parameters,
+                    value_parameters: declared_value_parameters,
+                    return_type,
+                } = function_type_constructor.node;
+
+                let type_parameters = declared_type_parameters.map(|identifiers| {
+                    identifiers
+                        .into_iter()
+                        .map(|identifier| identifier.node)
+                        .collect()
+                });
+                let mut value_parameters = Vec::with_capacity(declared_value_parameters.len());
+
+                for parameter in declared_value_parameters {
+                    let r#type = parameter.construct(&context)?;
+
+                    value_parameters.push(r#type);
+                }
+
+                let return_type = Box::new(return_type.construct(&context)?);
+
+                Type::Function {
+                    type_parameters,
+                    value_parameters,
+                    return_type,
+                }
+            }
             TypeConstructor::Identifier(WithPosition {
                 node: identifier, ..
             }) => {
diff --git a/dust-lang/src/abstract_tree/value_node.rs b/dust-lang/src/abstract_tree/value_node.rs
index 949c73e..ad8d64a 100644
--- a/dust-lang/src/abstract_tree/value_node.rs
+++ b/dust-lang/src/abstract_tree/value_node.rs
@@ -347,10 +347,10 @@ impl ExpectedType for ValueNode {
             } => {
                 let mut value_parameter_types = Vec::with_capacity(value_parameters.len());
 
-                for (identifier, type_constructor) in value_parameters {
+                for (_, type_constructor) in value_parameters {
                     let r#type = type_constructor.clone().construct(&context)?;
 
-                    value_parameter_types.push((identifier.clone(), r#type));
+                    value_parameter_types.push(r#type);
                 }
 
                 let type_parameters = type_parameters.clone().map(|parameters| {
diff --git a/dust-lang/src/value.rs b/dust-lang/src/value.rs
index 5bb713f..55703ef 100644
--- a/dust-lang/src/value.rs
+++ b/dust-lang/src/value.rs
@@ -234,11 +234,20 @@ impl ValueInner {
             ValueInner::Map(_) => Type::Map,
             ValueInner::Range(_) => Type::Range,
             ValueInner::String(_) => Type::String,
-            ValueInner::Function(function) => Type::Function {
-                type_parameters: None,
-                value_parameters: function.value_parameters.clone(),
-                return_type: Box::new(function.return_type.clone()),
-            },
+            ValueInner::Function(function) => {
+                let value_parameters = function
+                    .value_parameters()
+                    .into_iter()
+                    .map(|(_, r#type)| r#type)
+                    .cloned()
+                    .collect();
+
+                Type::Function {
+                    type_parameters: function.type_parameters().clone(),
+                    value_parameters,
+                    return_type: Box::new(function.return_type.clone()),
+                }
+            }
             ValueInner::Structure { name, .. } => {
                 if let Some(r#type) = context.get_type(&name.node)? {
                     r#type
@@ -328,6 +337,10 @@ impl Function {
         &self.type_parameters
     }
 
+    pub fn value_parameters(&self) -> &Vec<(Identifier, Type)> {
+        &self.value_parameters
+    }
+
     pub fn call(
         self,
         arguments: Vec<Value>,