diff --git a/crates/aiken-lang/src/parser.rs b/crates/aiken-lang/src/parser.rs
index ad44e384..d3eea0a3 100644
--- a/crates/aiken-lang/src/parser.rs
+++ b/crates/aiken-lang/src/parser.rs
@@ -235,14 +235,14 @@ pub fn type_alias_parser() -> impl Parser<Token, ast::UntypedDefinition, Error =
 
 pub fn validator_parser() -> impl Parser<Token, ast::UntypedDefinition, Error = ParseError> {
     just(Token::Validator)
-        .ignore_then(select! {Token::Name {name} => name})
+        .ignore_then(select! {Token::Name {name} => name}.map_with_span(|name, span| (name, span)))
         .then(
             fn_param_parser()
                 .separated_by(just(Token::Comma))
                 .allow_trailing()
                 .delimited_by(just(Token::LeftParen), just(Token::RightParen))
-                .or_not()
-                .map_with_span(|arguments, span| (arguments.unwrap_or_default(), span)),
+                .map_with_span(|arguments, span| (arguments, span))
+                .or_not(),
         )
         .then(
             just(Token::Fn)
@@ -284,8 +284,10 @@ pub fn validator_parser() -> impl Parser<Token, ast::UntypedDefinition, Error =
                 )
                 .delimited_by(just(Token::LeftBrace), just(Token::RightBrace)),
         )
-        .map_with_span(|((name, (params, params_span)), mut fun), span| {
-            fun.name = name;
+        .map_with_span(|((name, opt_extra_params), mut fun), span| {
+            fun.name = name.0;
+
+            let (params, params_span) = opt_extra_params.unwrap_or((vec![], name.1));
 
             ast::UntypedDefinition::Validator(ast::Validator {
                 doc: None,
diff --git a/crates/aiken-lang/src/parser/lexer.rs b/crates/aiken-lang/src/parser/lexer.rs
index 9b390364..25968703 100644
--- a/crates/aiken-lang/src/parser/lexer.rs
+++ b/crates/aiken-lang/src/parser/lexer.rs
@@ -102,6 +102,7 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = ParseError> {
         "todo" => Token::Todo,
         "type" => Token::Type,
         "when" => Token::When,
+        "validator" => Token::Validator,
         _ => {
             if s.chars().next().map_or(false, |c| c.is_uppercase()) {
                 Token::UpName {
diff --git a/crates/aiken-lang/src/tests/parser.rs b/crates/aiken-lang/src/tests/parser.rs
index 698f202b..0a945fb9 100644
--- a/crates/aiken-lang/src/tests/parser.rs
+++ b/crates/aiken-lang/src/tests/parser.rs
@@ -50,12 +50,56 @@ fn validator() {
 
     assert_definitions(
         code,
-        vec![ast::UntypedDefinition::Use(Use {
-            location: Span::new((), 0..12),
-            module: vec!["std".to_string(), "list".to_string()],
-            as_name: None,
-            unqualified: vec![],
-            package: (),
+        vec![ast::UntypedDefinition::Validator(ast::Validator {
+            doc: None,
+            end_position: 54,
+            fun: Function {
+                arguments: vec![
+                    ast::Arg {
+                        arg_name: ast::ArgName::Named {
+                            name: "datum".to_string(),
+                            label: "datum".to_string(),
+                            location: Span::new((), 21..26),
+                        },
+                        location: Span::new((), 21..26),
+                        annotation: None,
+                        tipo: (),
+                    },
+                    ast::Arg {
+                        arg_name: ast::ArgName::Named {
+                            name: "rdmr".to_string(),
+                            label: "rdmr".to_string(),
+                            location: Span::new((), 28..32),
+                        },
+                        location: Span::new((), 28..32),
+                        annotation: None,
+                        tipo: (),
+                    },
+                    ast::Arg {
+                        arg_name: ast::ArgName::Named {
+                            name: "ctx".to_string(),
+                            label: "ctx".to_string(),
+                            location: Span::new((), 34..37),
+                        },
+                        location: Span::new((), 34..37),
+                        annotation: None,
+                        tipo: (),
+                    },
+                ],
+                body: expr::UntypedExpr::Var {
+                    location: Span::new((), 45..49),
+                    name: "True".to_string(),
+                },
+                doc: None,
+                location: Span::new((), 18..38),
+                name: "foo".to_string(),
+                public: false,
+                return_annotation: None,
+                return_type: (),
+                end_position: 52,
+            },
+            location: Span::new((), 0..13),
+            params: vec![],
         })],
     )
 }
diff --git a/examples/hello_world/validators/hello_world.ak b/examples/hello_world/validators/hello_world.ak
index 6069b1d7..1fe1b788 100644
--- a/examples/hello_world/validators/hello_world.ak
+++ b/examples/hello_world/validators/hello_world.ak
@@ -12,11 +12,14 @@ type Redeemer {
   msg: ByteArray,
 }
 
-fn spend(datum: Datum, redeemer: Redeemer, context: ScriptContext) -> Bool {
-  let must_say_hello = string.from_bytearray(redeemer.msg) == "Hello, World!"
+validator spend {
+  fn(datum: Datum, redeemer: Redeemer, context: ScriptContext) -> Bool {
+    let must_say_hello = string.from_bytearray(redeemer.msg) == "Hello, World!"
 
-  let must_be_signed =
-    list.has(context.transaction.extra_signatories, datum.owner)
+    let must_be_signed =
+      list.has(context.transaction.extra_signatories, datum.owner)
 
-  must_say_hello && must_be_signed
+    must_say_hello && must_be_signed
+  }
 }
+