diff --git a/lib/ace/ace-evaluator/lib/yaml-cpp/src/emitterutils.cpp b/lib/ace/ace-evaluator/lib/yaml-cpp/src/emitterutils.cpp
index 588c855..b5f9851 100644
--- a/lib/ace/ace-evaluator/lib/yaml-cpp/src/emitterutils.cpp
+++ b/lib/ace/ace-evaluator/lib/yaml-cpp/src/emitterutils.cpp
@@ -1,5 +1,6 @@
 #include <algorithm>
 #include <iomanip>
+#include <cstdint> 
 #include <sstream>
 
 #include "emitterutils.h"