diff --git a/config/rules.mk b/config/rules.mk
index 8f369a0e5a9e..f467842f054f 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -62,6 +62,11 @@ else
 EXEC			= exec
 endif
 
+# Don't copy xulrunner files at install time, when using system xulrunner
+ifdef SYSTEM_LIBXUL
+  SKIP_COPY_XULRUNNER=1
+endif
+
 # ELOG prints out failed command when building silently (gmake -s).
 ifneq (,$(findstring -s,$(MAKEFLAGS)))
   ELOG := $(EXEC) sh $(BUILD_TOOLS)/print-failed-commands.sh
diff --git a/configure.in b/configure.in
index 67a9bb8ad3fc..e1ea4630fe5c 100644
--- a/configure.in
+++ b/configure.in
@@ -4038,6 +4038,16 @@ else
 fi
 AC_SUBST(LIBXUL_DIST)
 
+SYSTEM_LIBXUL=
+
+MOZ_ARG_WITH_BOOL(system-libxul,
+[  --with-system-libxul   Use system installed libxul SDK],
+    SYSTEM_LIBXUL=1)
+
+if test -n "$SYSTEM_LIBXUL" && test -z "$MOZ_ENABLE_LIBXUL"; then
+    AC_MSG_ERROR([--with-system-libxul needs --with-libxul-sdk])
+fi
+
 dnl ========================================================
 dnl = If NSPR was not detected in the system, 
 dnl = use the one in the source tree (mozilla/nsprpub)
@@ -7933,6 +7943,7 @@ COMPILE_CXXFLAGS=`echo \
     $COMPILE_CXXFLAGS`
 
 AC_SUBST(SYSTEM_MAKEDEPEND)
+AC_SUBST(SYSTEM_LIBXUL)
 AC_SUBST(SYSTEM_JPEG)
 AC_SUBST(SYSTEM_PNG)
 AC_SUBST(SYSTEM_ZLIB)