diff --git a/PKGBUILD b/PKGBUILD
index 5d75bf1..3629edb 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -9,7 +9,7 @@ pkgrel=1
 arch=('i686' 'x86_64')
 url="http://www.kernel.org/"
 license=('GPL2')
-makedepends=('xmlto' 'docbook-xsl' 'kmod' 'inetutils' 'bc')
+makedepends=('xmlto' 'docbook-xsl' 'kmod' 'inetutils' 'bc' 'elfutils')
 options=('!strip')
 source=("https://www.kernel.org/pub/linux/kernel/v4.x/${_srcname}.tar.xz"
         "https://www.kernel.org/pub/linux/kernel/v4.x/${_srcname}.tar.sign"
@@ -243,6 +243,12 @@ _package-headers() {
     cp ${i} "${pkgdir}/usr/lib/modules/${_kernver}/build/${i}"
   done
 
+  # add objtool for external module building and enabled VALIDATION_STACK option
+  if [ -f tools/objtool/objtool ];  then
+      mkdir -p "${pkgdir}/usr/lib/modules/${_kernver}/build/tools/objtool"
+      cp -a tools/objtool/objtool ${pkgdir}/usr/lib/modules/${_kernver}/build/tools/objtool/ 
+  fi
+
   chown -R root.root "${pkgdir}/usr/lib/modules/${_kernver}/build"
   find "${pkgdir}/usr/lib/modules/${_kernver}/build" -type d -exec chmod 755 {} \;