diff --git a/src/ast/Definition.cpp b/src/ast/Definition.cpp
index 28677c7d..94bb3dc6 100644
--- a/src/ast/Definition.cpp
+++ b/src/ast/Definition.cpp
@@ -692,13 +692,13 @@ void InvariantDefinition::accept( Visitor& visitor )
 //
 
 StructureDefinition::StructureDefinition(
-    const Identifier::Ptr& identifier, const NodeList< FunctionDefinition >::Ptr& functions )
+    const Identifier::Ptr& identifier, const FunctionDefinitions::Ptr& functions )
 : Definition( Node::ID::STRUCTURE_DEFINITION, identifier )
 , m_functions( functions )
 {
 }
 
-const NodeList< FunctionDefinition >::Ptr& StructureDefinition::functions( void ) const
+const FunctionDefinitions::Ptr& StructureDefinition::functions( void ) const
 {
     return m_functions;
 }
diff --git a/src/ast/Definition.h b/src/ast/Definition.h
index a5660c17..9f0e7c63 100644
--- a/src/ast/Definition.h
+++ b/src/ast/Definition.h
@@ -434,15 +434,14 @@ namespace libcasm_fe
             using Ptr = std::shared_ptr< StructureDefinition >;
 
             StructureDefinition(
-                const Identifier::Ptr& identifier,
-                const NodeList< FunctionDefinition >::Ptr& functions );
+                const Identifier::Ptr& identifier, const FunctionDefinitions::Ptr& functions );
 
-            const NodeList< FunctionDefinition >::Ptr& functions( void ) const;
+            const FunctionDefinitions::Ptr& functions( void ) const;
 
             void accept( Visitor& visitor ) override final;
 
           private:
-            const NodeList< FunctionDefinition >::Ptr m_functions;
+            const FunctionDefinitions::Ptr m_functions;
         };
 
         class FeatureDefinition final : public Definition