diff --git a/crates/nu-protocol/src/engine/stack.rs b/crates/nu-protocol/src/engine/stack.rs
index 9315744dfb..e963227ca8 100644
--- a/crates/nu-protocol/src/engine/stack.rs
+++ b/crates/nu-protocol/src/engine/stack.rs
@@ -277,7 +277,7 @@ impl Stack {
     }
 
     pub fn gather_captures(&self, engine_state: &EngineState, captures: &[VarId]) -> Stack {
-        let mut vars = vec![];
+        let mut vars = Vec::with_capacity(captures.len());
 
         let fake_span = Span::new(0, 0);