diff --git a/src/libs/ifc/ifcdef.h b/src/libs/ifc/ifcdef.h
index 4dceb4b48..9f72d92da 100644
--- a/src/libs/ifc/ifcdef.h
+++ b/src/libs/ifc/ifcdef.h
@@ -31,6 +31,7 @@
 
 #include <QtGlobal>
 #include "../vmisc/def.h"
+#include <ciso646> //for msvc
 
 extern const QString CustomMSign;
 extern const QString CustomIncrSign;
diff --git a/src/libs/vdxf/dxfdef.h b/src/libs/vdxf/dxfdef.h
index 6d70eada1..6e5da7729 100644
--- a/src/libs/vdxf/dxfdef.h
+++ b/src/libs/vdxf/dxfdef.h
@@ -30,6 +30,7 @@
 #define DXFDEF_H
 
 #include <QtGlobal>
+#include <ciso646> //for msvc
 
 enum class VarMeasurement : unsigned char { English=0, Metric=1 };
 
diff --git a/src/libs/vlayout/vlayoutdef.h b/src/libs/vlayout/vlayoutdef.h
index 3c58dbdde..a5e86c87d 100644
--- a/src/libs/vlayout/vlayoutdef.h
+++ b/src/libs/vlayout/vlayoutdef.h
@@ -29,6 +29,8 @@
 #ifndef VLAYOUTDEF_H
 #define VLAYOUTDEF_H
 
+#include <ciso646> //for msvc
+
 enum class EquidistantType : char { OpenEquidistant, CloseEquidistant };
 
 enum class LayoutErrors : char
diff --git a/src/libs/vmisc/def.h b/src/libs/vmisc/def.h
index 6aca40422..14bc77b8f 100644
--- a/src/libs/vmisc/def.h
+++ b/src/libs/vmisc/def.h
@@ -37,6 +37,7 @@
 #endif /* Q_OS_WIN */
 
 #include "debugbreak.h"
+#include <ciso646> //for msvc
 
 class QComboBox;