diff --git a/src/os2/menu.cpp b/src/os2/menu.cpp
index cfbb69829a..3d9755066c 100644
--- a/src/os2/menu.cpp
+++ b/src/os2/menu.cpp
@@ -17,6 +17,7 @@
 #include "wx/wxprec.h"
 
 #ifndef WX_PRECOMP
+    #include "wx/app.h"
     #include "wx/frame.h"
     #include "wx/menu.h"
     #include "wx/utils.h"
diff --git a/src/os2/radiobox.cpp b/src/os2/radiobox.cpp
index 40e46cd1cc..0392b1c87f 100644
--- a/src/os2/radiobox.cpp
+++ b/src/os2/radiobox.cpp
@@ -15,6 +15,8 @@
 #ifndef WX_PRECOMP
     #include <stdio.h>
     #include "wx/setup.h"
+    #include "wx/wxchar.h"
+    #include "wx/string.h"
     #include "wx/bitmap.h"
     #include "wx/brush.h"
     #include "wx/radiobox.h"