--- a/toolkit/mozapps/installer/upload-files.mk
+++ b/toolkit/mozapps/installer/upload-files.mk
@@ -315,26 +315,16 @@ endif
 GARBAGE		+= $(DIST)/$(PACKAGE) $(PACKAGE)
 
 # The following target stages files into two directories: one directory for
 # core files, and one for optional extensions based on the information in
 # the MOZ_PKG_MANIFEST file.
 
 PKG_ARG = , '$(pkg)'
 
-# MOZ_PKG_MANIFEST is the canonical way to define the package manifest (which
-# the packager will preprocess), but for a smooth transition, we derive it
-# from the now deprecated MOZ_PKG_MANIFEST_P when MOZ_PKG_MANIFEST is not
-# defined.
-ifndef MOZ_PKG_MANIFEST
-  ifdef MOZ_PKG_MANIFEST_P
-    MOZ_PKG_MANIFEST := $(MOZ_PKG_MANIFEST_P)
-  endif # MOZ_PKG_MANIFEST_P
-endif # MOZ_PKG_MANIFEST
-
 ifndef MOZ_PACKAGER_FORMAT
   MOZ_PACKAGER_FORMAT = $(error MOZ_PACKAGER_FORMAT is not set)
 endif
 
 ifneq (android,$(MOZ_WIDGET_TOOLKIT))
   OPTIMIZEJARS = 1
   JAR_COMPRESSION ?= none
 endif