diff --git a/src/twopass.rs b/src/twopass.rs
index 88f1937..846c66b 100644
--- a/src/twopass.rs
+++ b/src/twopass.rs
@@ -396,7 +396,7 @@ impl OpenFunction {
 
 #[cfg(test)]
 mod tests {
-	use crate::ast::*;
+	use crate::{ast::*, types::ValueInner};
 
 	use super::build;
 
@@ -459,4 +459,25 @@ mod tests {
 		assert_eq!(ret, Some(42.into()));
 		assert_eq!(env.get("x".into()), Some(666.into()));
 	}
+
+	#[test]
+	fn test_capture() {
+		let remember = Function {
+			name: Some("remember".into()),
+			args: vec!["value".into()],
+			body: vec![],
+			ret: Some(Box::new(Expression::Function(Function {
+				name: None,
+				args: vec![],
+				body: vec![],
+				ret: Some(Box::new(Expression::new_variable("value"))),
+			}))),
+		};
+		let remember = build(&remember);
+		let the_answerer = remember.call(None, &[Some(42.into())]);
+		let Some(ValueInner::Function(f)) = the_answerer else {
+			panic!("a function expected");
+		};
+		assert_eq!(f.call(&[]), Some(42.into()));
+	}
 }