diff --git a/config/rules.mk b/config/rules.mk
index e40e1792b5d..d6fad629473 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -1158,18 +1158,6 @@ ifneq (,$(DIST_SUBDIR)$(XPI_NAME))
 PREF_DIR = defaults/preferences
 endif
 
-################################################################################
-# Copy each element of AUTOCFG_JS_EXPORTS to $(FINAL_TARGET)/defaults/autoconfig
-
-ifneq ($(AUTOCFG_JS_EXPORTS),)
-ifndef NO_DIST_INSTALL
-AUTOCFG_JS_EXPORTS_FILES := $(AUTOCFG_JS_EXPORTS)
-AUTOCFG_JS_EXPORTS_DEST := $(FINAL_TARGET)/defaults/autoconfig
-AUTOCFG_JS_EXPORTS_TARGET := export
-INSTALL_TARGETS += AUTOCFG_JS_EXPORTS
-endif
-endif
-
 ################################################################################
 # SDK
 
diff --git a/extensions/pref/autoconfig/src/Makefile.in b/extensions/pref/autoconfig/src/Makefile.in
deleted file mode 100644
index 830f5ae62ab..00000000000
--- a/extensions/pref/autoconfig/src/Makefile.in
+++ /dev/null
@@ -1,7 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-AUTOCFG_JS_EXPORTS = \
-		$(srcdir)/prefcalls.js \
-		$(NULL)
diff --git a/extensions/pref/autoconfig/src/moz.build b/extensions/pref/autoconfig/src/moz.build
index 0b9e7f12bf0..2f493bbcc7c 100644
--- a/extensions/pref/autoconfig/src/moz.build
+++ b/extensions/pref/autoconfig/src/moz.build
@@ -15,3 +15,7 @@ FINAL_LIBRARY = 'xul'
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
+
+FINAL_TARGET_FILES.defaults.autoconfig += [
+    'prefcalls.js',
+]