diff --git a/src/frontends/qt4/GuiBox.cpp b/src/frontends/qt4/GuiBox.cpp
index 71546b4d1a..684fdc3266 100644
--- a/src/frontends/qt4/GuiBox.cpp
+++ b/src/frontends/qt4/GuiBox.cpp
@@ -30,6 +30,10 @@
 #include <QPushButton>
 #include <QLineEdit>
 
+#ifdef IN
+#undef IN
+#endif
+
 using namespace std;
 
 
diff --git a/src/frontends/qt4/GuiCharacter.h b/src/frontends/qt4/GuiCharacter.h
index 519ead0153..e590521a3e 100644
--- a/src/frontends/qt4/GuiCharacter.h
+++ b/src/frontends/qt4/GuiCharacter.h
@@ -20,6 +20,9 @@
 
 #include <utility>
 
+#ifdef IGNORE
+#undef IGNORE
+#endif
 
 namespace lyx {
 namespace frontend {