diff --git a/Makefile.in b/Makefile.in
index 3abf9a4138..f5000687a7 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1532,6 +1532,15 @@ COND_TOOLKIT_X11_BASE_MACOSX_HDR =  \
 @COND_TOOLKIT_X11@BASE_MACOSX_HDR = $(COND_TOOLKIT_X11_BASE_MACOSX_HDR)
 @COND_PLATFORM_MACOSX_1@BASE_PLATFORM_HDR = $(BASE_MACOSX_HDR)
 @COND_PLATFORM_MSDOS_1@BASE_PLATFORM_HDR = wx/msdos/mimetype.h
+COND_PLATFORM_OS2_1_BASE_PLATFORM_HDR =  \
+	wx/os2/apptbase.h \
+	wx/os2/apptrait.h \
+	wx/os2/mimetype.h \
+	wx/os2/private.h \
+	wx/os2/stdpaths.h \
+	wx/os2/chkconf.h \
+	wx/os2/wxrsc.h
+@COND_PLATFORM_OS2_1@BASE_PLATFORM_HDR = $(COND_PLATFORM_OS2_1_BASE_PLATFORM_HDR)
 COND_PLATFORM_UNIX_1_BASE_PLATFORM_HDR =  \
 	wx/unix/apptbase.h \
 	wx/unix/apptrait.h \