diff --git a/neural_network/lstm.py b/neural_network/lstm.py
index c9d11d905..9ac507924 100644
--- a/neural_network/lstm.py
+++ b/neural_network/lstm.py
@@ -461,7 +461,7 @@ class LongShortTermMemory:
 
             self.backward_pass(errors, inputs)
 
-    def test(self) -> None:
+    def test(self) -> str:
         """
         Test the LSTM model.