diff --git a/OndselSolver/FunctionX.cpp b/OndselSolver/FunctionX.cpp
index 7c4f683..461653c 100644
--- a/OndselSolver/FunctionX.cpp
+++ b/OndselSolver/FunctionX.cpp
@@ -6,6 +6,8 @@
  *   See LICENSE file for details about copyright.                         *
  ***************************************************************************/
 
+#include <algorithm>
+
 #include "FunctionX.h"
 #include "Constant.h"
 #include "Sum.h"
diff --git a/OndselSolver/SymbolicParser.cpp b/OndselSolver/SymbolicParser.cpp
index 6860f95..76f9ac4 100644
--- a/OndselSolver/SymbolicParser.cpp
+++ b/OndselSolver/SymbolicParser.cpp
@@ -9,6 +9,7 @@
 #include "corecrt_math_defines.h"
 #include <sstream>
 #include <iomanip>
+#include <algorithm>
 
 #include "SymbolicParser.h"
 #include "BasicUserFunction.h"