diff --git a/src/General/ExprtkWrapper.cpp b/src/General/ExprtkWrapper.cpp
index cf6144f6fd9a44f2a2dc8339d2c07b670bd235c8..6a704530c289cce481be711f098b9d6e0a454b26 100644
--- a/src/General/ExprtkWrapper.cpp
+++ b/src/General/ExprtkWrapper.cpp
@@ -11,6 +11,7 @@
 #include "ExprtkWrapper.h"
 #include "ExprtkWrapperSerialization.h"
 #include "exceptions.h"
+#include <string>
 
 BOOST_CLASS_EXPORT_IMPLEMENT(ExprtkWrapper);
 
diff --git a/src/General/ExprtkWrapper.h b/src/General/ExprtkWrapper.h
index f77bf824ca8169efa7a82313f1e6f7fb754b8d78..138d2dbc7760aee746c54aa043497a702f79ef8f 100644
--- a/src/General/ExprtkWrapper.h
+++ b/src/General/ExprtkWrapper.h
@@ -10,6 +10,7 @@
 
 #include <memory>
 #include <vector>
+#include <string>
 
 #include "../settings.h"