diff --git a/src/interpreter2/VirtualSchematikaMachine.cpp b/src/interpreter2/VirtualSchematikaMachine.cpp
index 5882dc89..012b16f6 100644
--- a/src/interpreter2/VirtualSchematikaMachine.cpp
+++ b/src/interpreter2/VirtualSchematikaMachine.cpp
@@ -4,6 +4,7 @@
  **/
 
 #include "VirtualSchematikaMachine.hpp"
+#include <xo/expression2/IExpression_DConstant.hpp>
 #include <xo/expression2/DConstant.hpp>
 #include <cassert>