diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53911dc0..1e3d1d6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+**Core**
+
+- Fixed `MessageHistory.to_list()` returning a reference to the internal list instead of a copy, causing simulator logs to contain future conversation messages that hadn't occurred at the time of logging. (PR: #PR_NUMBER_PLACEHOLDER)
+
 ### Added
 
 **Core**
diff --git a/maseval/core/history.py b/maseval/core/history.py
index 49ba8ee6..0703f572 100644
--- a/maseval/core/history.py
+++ b/maseval/core/history.py
@@ -110,7 +110,7 @@ def to_list(self) -> List[Dict[str, Any]]:
         Returns:
             List of message dictionaries in OpenAI format
         """
-        return self._messages
+        return list(self._messages)
 
     def add_message(
         self,