diff --git a/PKGBUILD b/PKGBUILD
index 70df8a2..c5f0495 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -28,7 +28,7 @@ sha256sums=('SKIP'
 
 export KBUILD_BUILD_HOST=archlinux
 export KBUILD_BUILD_USER=$pkgbase
-export KBUILD_BUILD_TIMESTAMP="@${SOURCE_DATE_EPOCH:-$(date +%s)}"
+export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"
 
 prepare() {
   cd $_srcname