diff --git a/libs/EXTERNAL/libtatum/CMakeLists.txt b/libs/EXTERNAL/libtatum/CMakeLists.txt
index 3b9f10f560b..29d78daf0e0 100644
--- a/libs/EXTERNAL/libtatum/CMakeLists.txt
+++ b/libs/EXTERNAL/libtatum/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.16)
 
 project("tatum")
 
+# Parallel tatum gives non-deterministic results. Use serial by default until resolved
 set(TATUM_EXECUTION_ENGINE "serial" CACHE STRING "Specify the framework for (potential) parallel execution")
 set_property(CACHE TATUM_EXECUTION_ENGINE PROPERTY STRINGS auto serial tbb)