diff --git a/src/run.rs b/src/run.rs
index 39f0182..fa0e677 100644
--- a/src/run.rs
+++ b/src/run.rs
@@ -99,7 +99,7 @@ impl Eval for Expression {
 				let Some(function) = scope.functions.get(callee.as_str()).cloned() else {
 					panic!("attempt to call non-existent function {callee}")
 				};
-				let args = args.into_iter().map(|arg| arg.eval(scope)).collect();
+				let args = args.iter().map(|arg| arg.eval(scope)).collect();
 				(function.inner)(scope, args)
 			}
 		}