diff --git a/parser/src/ast.rs b/parser/src/ast.rs
index 8b29051..b82abc8 100644
--- a/parser/src/ast.rs
+++ b/parser/src/ast.rs
@@ -3,13 +3,13 @@ use serde::Serialize;
 #[derive(Debug, Clone, Serialize)]
 pub struct Identifier(pub String);
 
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct FieldList(pub Vec<(Identifier, Visibility, TypeExpr)>);
 
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct ParamList(pub Vec<VarDecl>);
 
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct Block(pub Vec<Statement>);
 
 #[derive(Debug, Clone, Serialize)]
@@ -95,7 +95,7 @@ pub enum TopLevelKind {
     },
 }
 
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct Generics(pub Vec<(Identifier, Vec<Path>)>);
 
 #[derive(Debug, Clone, Serialize)]
diff --git a/parser/src/lib.rs b/parser/src/lib.rs
index 79886ac..062f0af 100644
--- a/parser/src/lib.rs
+++ b/parser/src/lib.rs
@@ -260,8 +260,8 @@ impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {
                 name: Identifier::from(inner.next().unwrap()),
                 generics: consume_rule(&mut inner, Rule::generics)
                     .map(Generics::from)
-                    .unwrap_or(Generics(Vec::new())),
-                fields: FieldList::from(inner.next().unwrap()),
+                    .unwrap_or_default(),
+                fields: inner.next().map(FieldList::from).unwrap_or_default(),
             },
 
             Rule::class_decl => TopLevelKind::ClassDecl {
diff --git a/test/src/main.mist b/test/src/main.mist
index 6996a76..602dd59 100644
--- a/test/src/main.mist
+++ b/test/src/main.mist
@@ -2,8 +2,6 @@ mod my_class;
 use <my_class::MyClass>;
 use <my_class::MyEnum>;
 
-struct Test<T> {}
-
 void main() {
     var my_class = new MyClass("World");
     my_class.greet();