diff --git a/trunk_parser/src/ast.rs b/trunk_parser/src/ast.rs
index 2ebaf33..48b0fdb 100644
--- a/trunk_parser/src/ast.rs
+++ b/trunk_parser/src/ast.rs
@@ -352,7 +352,7 @@ pub enum Expression {
     },
     Closure {
         params: Vec<Param>,
-        uses: Vec<Expression>,
+        uses: Vec<ClosureUse>,
         return_type: Option<Type>,
         body: Block
     },
@@ -438,6 +438,12 @@ pub enum Expression {
     },
 }
 
+#[derive(Debug, PartialEq, Clone, Serialize)]
+pub struct ClosureUse {
+    pub var: Expression,
+    pub by_ref: bool,
+}
+
 #[derive(Debug, PartialEq, Clone, Serialize)]
 pub struct MatchArm {
     pub conditions: Option<Vec<Expression>>,
diff --git a/trunk_parser/src/parser/mod.rs b/trunk_parser/src/parser/mod.rs
index f197bf4..6a500f1 100644
--- a/trunk_parser/src/parser/mod.rs
+++ b/trunk_parser/src/parser/mod.rs
@@ -1,6 +1,6 @@
 use std::{vec::IntoIter, fmt::{Display}};
 use trunk_lexer::{Token, TokenKind, Span};
-use crate::{Program, Statement, Block, Expression, ast::{ArrayItem, Use, MethodFlag, ClassFlag, ElseIf, UseKind, MagicConst, BackedEnumType}, Identifier, Type, MatchArm, Catch, Case};
+use crate::{Program, Statement, Block, Expression, ast::{ArrayItem, Use, MethodFlag, ClassFlag, ElseIf, UseKind, MagicConst, BackedEnumType, ClosureUse}, Identifier, Type, MatchArm, Catch, Case};
 
 type ParseResult<T> = Result<T, ParseError>;
 
@@ -1144,9 +1144,19 @@ impl Parser {
                     self.lparen()?;
 
                     while self.current.kind != TokenKind::RightParen {
-                        let var = match self.expression(0)? {
-                            s @ Expression::Variable { .. } => s,
-                            _ => return Err(ParseError::UnexpectedToken("expected variable".into(), self.current.span))
+                        let var = match self.current.kind {
+                            TokenKind::Ampersand => {
+                                self.next();
+
+                                match self.expression(0)? {
+                                    s @ Expression::Variable { .. } => ClosureUse { var: s, by_ref: true },
+                                    _ => return Err(ParseError::UnexpectedToken("expected variable".into(), self.current.span))
+                                }
+                            },
+                            _ => match self.expression(0)? {
+                                s @ Expression::Variable { .. } => ClosureUse { var: s, by_ref: false },
+                                _ => return Err(ParseError::UnexpectedToken("expected variable".into(), self.current.span))
+                            }
                         };
 
                         uses.push(var);