diff --git a/src/frontends/qt4/GuiViewSource.cpp b/src/frontends/qt4/GuiViewSource.cpp
index 991877bea7..b83082336f 100644
--- a/src/frontends/qt4/GuiViewSource.cpp
+++ b/src/frontends/qt4/GuiViewSource.cpp
@@ -23,7 +23,7 @@
 #include "Paragraph.h"
 #include "TexRow.h"
 
-#include "support/Debug.h"
+#include "support/debug.h"
 #include "support/lassert.h"
 #include "support/docstream.h"
 #include "support/gettext.h"