--- a/crates/jrsonnet-evaluator/src/builtin/mod.rs
+++ b/crates/jrsonnet-evaluator/src/builtin/mod.rs
@@ -379,7 +379,7 @@
 		1, to: ty!(number) => Val::Num;
 	], {
 		if to < from {
-			return Ok(Val::Arr(Rc::new(Vec::new())))
+			return Ok(Val::Arr(ArrValue::new_eager()))
 		}
 		let mut out = Vec::with_capacity((1+to as usize-from as usize).max(0));
 		for i in from as usize..=to as usize {
--- a/crates/jrsonnet-evaluator/src/val.rs
+++ b/crates/jrsonnet-evaluator/src/val.rs
@@ -179,6 +179,10 @@
 	Extended(Box<(Self, Self)>),
 }
 impl ArrValue {
+	pub fn new_eager() -> Self {
+		Self::Eager(Rc::new(Vec::new()))
+	}
+
 	pub fn len(&self) -> usize {
 		match self {
 			Self::Lazy(l) => l.len(),