diff --git a/config/baseconfig.mk b/config/baseconfig.mk
--- a/config/baseconfig.mk
+++ b/config/baseconfig.mk
@@ -1,14 +1,14 @@
 # This file is normally included by autoconf.mk, but it is also used
 # directly in python/mozbuild/mozbuild/base.py for gmake validation.
 # We thus use INCLUDED_AUTOCONF_MK to enable/disable some parts depending
 # whether a normal build is happening or whether the check is running.
-includedir := $(includedir)/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
-idldir = $(datadir)/idl/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
+includedir := $(includedir)/$(MOZ_APP_NAME)
+idldir = $(datadir)/idl/$(MOZ_APP_NAME)
 installdir = $(libdir)/$(MOZ_APP_NAME)-$(MOZ_APP_VERSION)
 sdkdir = $(libdir)/$(MOZ_APP_NAME)-devel-$(MOZ_APP_VERSION)
 ifndef TOP_DIST
 TOP_DIST = dist
 endif
 ifneq (,$(filter /%,$(TOP_DIST)))
 DIST = $(TOP_DIST)
 else