diff --git a/src/AudacityApp.cpp b/src/AudacityApp.cpp
index ef06b16a0..7baeb6267 100644
--- a/src/AudacityApp.cpp
+++ b/src/AudacityApp.cpp
@@ -15,7 +15,7 @@ It handles initialization and termination by subclassing wxApp.
 
 *//*******************************************************************/
 
-#include "Audacity.h" // This should always be included first; for USE_* macros
+#include "Audacity.h" // This should always be included first; for USE_* macros and __UNIX__
 #include "AudacityApp.h"
 
 #include "Experimental.h"
diff --git a/src/DirManager.cpp b/src/DirManager.cpp
index 9159d0b31..e0e0399e8 100644
--- a/src/DirManager.cpp
+++ b/src/DirManager.cpp
@@ -61,7 +61,7 @@
 *//*******************************************************************/
 
 
-#include "Audacity.h"
+#include "Audacity.h" // for __UNIX__
 #include "DirManager.h"
 
 #include "MemoryX.h"
diff --git a/src/FileFormats.h b/src/FileFormats.h
index 34297bb80..2960d9241 100644
--- a/src/FileFormats.h
+++ b/src/FileFormats.h
@@ -11,7 +11,7 @@
 #ifndef __AUDACITY_FILE_FORMATS__
 #define __AUDACITY_FILE_FORMATS__
 
-#include "Audacity.h"
+#include "Audacity.h" // for __UNIX__
 
 #include <wx/list.h>
 #include <wx/arrstr.h>