diff --git a/src/modular_candle_trait.rs b/src/modular_candle_trait.rs
index ee3db16..3e2d2ba 100644
--- a/src/modular_candle_trait.rs
+++ b/src/modular_candle_trait.rs
@@ -14,5 +14,5 @@ pub trait ModularCandle<T: TakerTrade>: Clone + Default {
     fn finalize(&mut self);
 
     /// Check if aggregation rule triggered has been triggered on candle
-    fn finalized(&mut self);
+    fn finalized(&mut self) -> bool;
 }