diff --git a/src/twopass.rs b/src/twopass.rs
index 6e148b0..4107818 100644
--- a/src/twopass.rs
+++ b/src/twopass.rs
@@ -548,4 +548,51 @@ mod tests {
 		let the_answerer = remember.call(None, &[Some(42.into())]);
 		assert_eq!(call(&the_answerer, &[]), Some(42.into()));
 	}
+
+	#[test]
+	fn test_rw() {
+		let make_cell = Function {
+			name: Some("make_cell".into()),
+			args: vec![],
+			body: vec![Statement::Local {
+				name: "data".into(),
+				init: None,
+			}],
+			ret: Some(Box::new(Expression::new_table(
+				[
+					(
+						"get",
+						Expression::Function(Function {
+							name: None,
+							args: vec![],
+							body: vec![],
+							ret: Some(Box::new(Expression::new_variable("data"))),
+						}),
+					),
+					(
+						"set",
+						Expression::Function(Function {
+							name: None,
+							args: vec!["value".into()],
+							body: vec![Statement::Assign {
+								target: Location::new_variable("data"),
+								source: Box::new(Expression::new_variable("value")),
+							}],
+							ret: None,
+						}),
+					),
+				]
+				.into_iter(),
+			))),
+		};
+		let make_cell = build(&make_cell);
+		let cell1 = make_cell.call(None, &[]);
+		let cell2 = make_cell.call(None, &[]);
+		assert_eq!(call(&get(&cell1, "get"), &[]), None);
+		call(&get(&cell1, "set"), &[Some(42.into())]);
+		call(&get(&cell2, "set"), &[Some("foobar".into())]);
+		assert_eq!(call(&get(&cell1, "get"), &[]), Some(42.into()));
+		call(&get(&cell1, "set"), &[call(&get(&cell2, "get"), &[])]);
+		assert_eq!(call(&get(&cell1, "get"), &[]), Some("foobar".into()));
+	}
 }