diff --git a/config/autoconf.mk.in b/config/autoconf.mk.in
--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -56,21 +56,21 @@ MOZ_APP_NAME	= @MOZ_APP_NAME@
 MOZ_APP_DISPLAYNAME = @MOZ_APP_DISPLAYNAME@
 MOZ_APP_VERSION = @MOZ_APP_VERSION@
 
 MOZ_PKG_SPECIAL = @MOZ_PKG_SPECIAL@
 
 prefix		= @prefix@
 exec_prefix	= @exec_prefix@
 bindir		= @bindir@
-includedir	= @includedir@/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
+includedir	= @includedir@/$(MOZ_APP_NAME)3
 libdir		= @libdir@
 datadir		= @datadir@
 mandir		= @mandir@
-idldir		= $(datadir)/idl/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
+idldir		= $(datadir)/idl/$(MOZ_APP_NAME)3
 
 installdir	= $(libdir)/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
 sdkdir		= $(libdir)/$(MOZ_APP_NAME)-devel-$(MOZ_APP_VERSION)
 
 MOZDEPTH	= $(DEPTH)/mozilla
 DIST		= $(MOZDEPTH)/dist
 LIBXUL_SDK      = @LIBXUL_SDK@