diff -up thunderbird-31.0/comm-esr31/client.mk.old thunderbird-31.0/comm-esr31/client.mk
--- thunderbird-31.0/comm-esr31/client.mk.old	2014-07-18 02:04:05.000000000 +0200
+++ thunderbird-31.0/comm-esr31/client.mk	2014-07-30 10:57:01.177453550 +0200
@@ -131,7 +131,7 @@ endif
 
 
 ifndef MOZ_OBJDIR
-  MOZ_OBJDIR = obj-$(CONFIG_GUESS)
+  MOZ_OBJDIR = objdir
 else
 # On Windows Pymake builds check MOZ_OBJDIR doesn't start with "/"
   ifneq (,$(findstring mingw,$(CONFIG_GUESS)))
diff -up thunderbird-31.0/comm-esr31/mozilla/media/webrtc/trunk/Makefile.old thunderbird-31.0/comm-esr31/mozilla/media/webrtc/trunk/Makefile