diff --git a/ThirdParty/ReadMe.md b/ThirdParty/ReadMe.md
index eb20c56a89268c8e3517dec285593f25bed6987b..8562dd872e3cc990697abdcc6446263dae3470f1 100644
--- a/ThirdParty/ReadMe.md
+++ b/ThirdParty/ReadMe.md
@@ -36,3 +36,7 @@ Is integrated as a submodule.
 
 Header only c++ json parser. Directly integrated because the benchmarks and
 tests are too large.
+
+## exprtk ##
+
+Header only c++ mathematical expression parsing and evaluation library