diff --git a/mozilla/Makefile.in b/mozilla/Makefile.in
index 7050e2548a4..ab4d3d26693 100644
--- a/mozilla/Makefile.in
+++ b/mozilla/Makefile.in
@@ -250,6 +250,10 @@ ifdef MOZ_PSM
 tier_50_dirs	+= security/manager
 endif
 
+ifdef MOZ_PREF_EXTENSIONS
+tier_50_dirs += extensions/pref
+endif
+
 ifdef MOZ_XUL_APP
 ifndef BUILD_STATIC_LIBS
 tier_50_dirs += toolkit/library
diff --git a/mozilla/config/autoconf.mk.in b/mozilla/config/autoconf.mk.in
index a7a920877c5..b57505731a5 100644
--- a/mozilla/config/autoconf.mk.in
+++ b/mozilla/config/autoconf.mk.in
@@ -202,6 +202,8 @@ MOZ_ENABLE_CANVAS = @MOZ_ENABLE_CANVAS@
 MOZ_CAIRO_CFLAGS = @MOZ_CAIRO_CFLAGS@
 MOZ_XSLT_STANDALONE = @MOZ_XSLT_STANDALONE@
 
+MOZ_PREF_EXTENSIONS = @MOZ_PREF_EXTENSIONS@
+
 # Mac's don't like / in a #include, so we include the libart
 # headers locally if we're using the external library
 ifdef MOZ_LIBART_CFLAGS
diff --git a/mozilla/configure.in b/mozilla/configure.in
index 208c2f23c67..d5f31e5d389 100644
--- a/mozilla/configure.in
+++ b/mozilla/configure.in
@@ -4038,7 +4038,7 @@ MOZ_BRANDING_DIRECTORY=
 MOZ_CALENDAR=
 MOZ_DBGRINFO_MODULES=
 MOZ_ENABLE_LIBXUL=
-MOZ_EXTENSIONS_ALL=" cookie wallet content-packs xml-rpc help p3p pref venkman inspector irc universalchardet typeaheadfind webservices spellcheck gnomevfs auth sroaming xmlterm datetime finger cview layout-debug tasks sql xforms permissions schema-validation reporter"
+MOZ_EXTENSIONS_ALL=" cookie wallet content-packs xml-rpc help p3p venkman inspector irc universalchardet typeaheadfind webservices spellcheck gnomevfs auth sroaming xmlterm datetime finger cview layout-debug tasks sql xforms permissions schema-validation reporter"
 MOZ_IMG_DECODERS_DEFAULT="png gif jpeg bmp xbm icon"
 MOZ_IMG_ENCODERS_DEFAULT="png jpeg"
 MOZ_IPCD=
@@ -4055,6 +4055,7 @@ MOZ_NO_FAST_LOAD=
 MOZ_OJI=1
 MOZ_PLAINTEXT_EDITOR_ONLY=
 MOZ_PLUGINS=1
+MOZ_PREF_EXTENSIONS=1
 MOZ_PROFILELOCKING=1
 MOZ_PROFILESHARING=1
 MOZ_PSM=1
@@ -4124,7 +4125,7 @@ suite)
   MOZ_SUITE=1
   MOZ_PROFILESHARING=
   MOZ_APP_VERSION=$SEAMONKEY_VERSION
-  MOZ_EXTENSIONS_DEFAULT=" cookie wallet content-packs xml-rpc help p3p pref venkman inspector irc universalchardet typeaheadfind webservices spellcheck gnomevfs auth sroaming permissions reporter"
+  MOZ_EXTENSIONS_DEFAULT=" cookie wallet content-packs xml-rpc help p3p venkman inspector irc universalchardet typeaheadfind webservices spellcheck gnomevfs auth sroaming permissions reporter"
   AC_DEFINE(MOZ_SUITE)
   ;;
 
@@ -4135,7 +4136,7 @@ browser)
   MOZ_UPDATER=1
   MOZ_PHOENIX=1
   MOZ_APP_VERSION=$FIREFOX_VERSION
-  MOZ_EXTENSIONS_DEFAULT=" cookie xml-rpc pref universalchardet webservices inspector gnomevfs auth permissions reporter"
+  MOZ_EXTENSIONS_DEFAULT=" cookie xml-rpc universalchardet webservices inspector gnomevfs auth permissions reporter"
   AC_DEFINE(MOZ_PHOENIX)
   ;;
 
@@ -4164,6 +4165,7 @@ minimo)
   MOZ_NO_FAST_LOAD=1
   MOZ_OJI=
   MOZ_PLAINTEXT_EDITOR_ONLY=1
+  MOZ_PREF_EXTENSIONS=
   MOZ_PROFILELOCKING=
   MOZ_PROFILESHARING=
   MOZ_SINGLE_PROFILE=1
@@ -4202,7 +4204,7 @@ mail)
   MOZ_STATIC_MAIL_BUILD=1
   MOZ_COMPOSER=1
   MOZ_APP_VERSION=$THUNDERBIRD_VERSION
-  MOZ_EXTENSIONS_DEFAULT=" wallet spellcheck pref webservices universalchardet auth"
+  MOZ_EXTENSIONS_DEFAULT=" wallet spellcheck webservices universalchardet auth"
   AC_DEFINE(MOZ_THUNDERBIRD)
   ;;
 
@@ -4237,7 +4239,7 @@ xulrunner)
   MOZ_XULRUNNER=1
   MOZ_ENABLE_LIBXUL=1
   MOZ_APP_VERSION=$MOZILLA_VERSION
-  MOZ_EXTENSIONS_DEFAULT=" xml-rpc pref universalchardet webservices gnomevfs auth"
+  MOZ_EXTENSIONS_DEFAULT=" xml-rpc universalchardet webservices gnomevfs auth"
   AC_DEFINE(MOZ_XULRUNNER)
   ;;
 
@@ -4246,6 +4248,7 @@ macbrowser)
   MOZ_APP_DISPLAYNAME=Mozilla
   MOZ_APP_VERSION=$MOZILLA_VERSION
   MOZ_EXTENSIONS_DEFAULT=" cookie universalchardet typeaheadfind permissions"
+  MOZ_PREF_EXTENSIONS=
   AC_DEFINE(MOZ_MACBROWSER)
   ;;
 
@@ -4264,7 +4267,11 @@ standalone)
   ;;
 
 *)
-  AC_MSG_ERROR([--enable-application=APP is required])
+  if test -z "$MOZ_BUILD_APP"; then
+    AC_MSG_ERROR([--enable-application=APP is required.])
+  else
+    AC_MSG_ERROR([--enable-application value not recognized.])
+  fi
   ;;
 
 esac
@@ -4876,6 +4883,16 @@ MOZ_ARG_DISABLE_BOOL(xmlextras,
     MOZ_XMLEXTRAS=,
     MOZ_XMLEXTRAS=1 )
 
+dnl ========================================================
+dnl Pref extensions (autoconfig and system-pref)
+dnl ========================================================
+MOZ_ARG_DISABLE_BOOL(pref-extensions,
+[  --disable-pref-extensions
+                          Disable pref extensions such as autoconfig and
+                          system-pref],
+  MOZ_PREF_EXTENSIONS=,
+  MOZ_PREF_EXTENSIONS=1 )
+
 dnl ========================================================
 dnl = Enable compilation of specific extension modules
 dnl ========================================================
@@ -4952,6 +4969,11 @@ if test `echo "$MOZ_EXTENSIONS" | grep -c xmlextras` -ne 0; then
     MOZ_EXTENSIONS=`echo $MOZ_EXTENSIONS | sed -e 's|xmlextras||g'`
 fi
 
+if test `echo "$MOZ_EXTENSIONS" | grep -c pref` -ne 0; then
+    AC_MSG_WARN([pref is no longer an extension, use --disable-pref-extensions to disable.])
+    MOZ_EXTENSIONS=`echo $MOZ_EXTENSIONS | sed -e 's|pref||g'`
+fi
+
 MOZ_ENABLE_JAVAXPCOM=
 JAVAC=
 JAR=
@@ -6781,6 +6803,7 @@ AC_SUBST(MINIMO)
 AC_SUBST(MOZ_MATHML)
 AC_SUBST(MOZ_XTF)
 AC_SUBST(MOZ_XMLEXTRAS)
+AC_SUBST(MOZ_PREF_EXTENSIONS)
 AC_SUBST(MOZ_SVG)
 AC_SUBST(MOZ_SVG_FOREIGNOBJECT)
 AC_SUBST(MOZ_SVG_RENDERER_GDIPLUS)
diff --git a/mozilla/extensions/pref/autoconfig/src/Makefile.in b/mozilla/extensions/pref/autoconfig/src/Makefile.in
index efbc3afd610..0448acf2187 100644
--- a/mozilla/extensions/pref/autoconfig/src/Makefile.in
+++ b/mozilla/extensions/pref/autoconfig/src/Makefile.in
@@ -48,7 +48,7 @@ endif
 EXPORT_LIBRARY   = 1
 IS_COMPONENT     = 1
 MODULE_NAME      = nsAutoConfigModule
-MOZILLA_INTERNAL_API = 1
+LIBXUL_LIBRARY   = 1
 
 PACKAGE_FILE     = autoconfig.pkg
 
diff --git a/mozilla/extensions/pref/system-pref/src/Makefile.in b/mozilla/extensions/pref/system-pref/src/Makefile.in
index 2f4d7cd2045..992d44b24b5 100644
--- a/mozilla/extensions/pref/system-pref/src/Makefile.in
+++ b/mozilla/extensions/pref/system-pref/src/Makefile.in
@@ -51,7 +51,7 @@ endif
 
 # We want to force the creation of a static lib.
 FORCE_STATIC_LIB = 1
-MOZILLA_INTERNAL_API = 1
+LIBXUL_LIBRARY = 1
 
 REQUIRES        = xpcom \
 		  string \
diff --git a/mozilla/extensions/pref/system-pref/src/gconf/Makefile.in b/mozilla/extensions/pref/system-pref/src/gconf/Makefile.in
index f6483f06247..334f2f23521 100644
--- a/mozilla/extensions/pref/system-pref/src/gconf/Makefile.in
+++ b/mozilla/extensions/pref/system-pref/src/gconf/Makefile.in
@@ -45,8 +45,7 @@ include $(DEPTH)/config/autoconf.mk
 
 MODULE = system-pref
 LIBRARY_NAME = system-pref
-GRE_MODULE	= 1
-MOZILLA_INTERNAL_API = 1
+LIBXUL_LIBRARY = 1
 
 REQUIRES        = pref \
 		  string \
diff --git a/mozilla/toolkit/library/libxul-config.mk b/mozilla/toolkit/library/libxul-config.mk
index c0df59d40e4..62e4c078dca 100644
--- a/mozilla/toolkit/library/libxul-config.mk
+++ b/mozilla/toolkit/library/libxul-config.mk
@@ -107,6 +107,7 @@ COMPONENT_LIBS += \
 	pippki \
 	pipboot \
 	pipnss \
+	autoconfig \
 	$(NULL)
 
 ifeq ($(OS_ARCH),WINNT)
@@ -138,6 +139,7 @@ endif
 
 ifdef MOZ_ENABLE_GTK2
 COMPONENT_LIBS += widget_gtk2
+COMPONENT_LIBS += system-pref
 endif
 
 ifneq (,$(MOZ_ENABLE_GTK)$(MOZ_ENABLE_GTK2))
diff --git a/mozilla/toolkit/library/nsStaticXULComponents.cpp b/mozilla/toolkit/library/nsStaticXULComponents.cpp
index 25ffdb800d6..0e8476e5620 100644
--- a/mozilla/toolkit/library/nsStaticXULComponents.cpp
+++ b/mozilla/toolkit/library/nsStaticXULComponents.cpp
@@ -145,6 +145,12 @@
 #define XREMOTE_MODULES
 #endif
 
+#ifdef MOZ_ENABLE_GTK2
+#define SYSTEMPREF_MODULES MODULE(system-pref)
+#else
+#define SYSTEMPREF_MODULES
+#endif
+
 #define XUL_MODULES                          \
     MODULE(xpcomObsoleteModule)              \
     MODULE(xpconnect)                        \
@@ -190,6 +196,8 @@
     MODULE(PKI)                              \
     MODULE(BOOT)                             \
     MODULE(NSS)                              \
+    MODULE(autoconfig)                       \
+    SYSTEMPREF_MODULES                       \
     /* end of list */
 
 #define MODULE(_name) \