diff --git a/build/debian/build.sh b/build/debian/build.sh
index 160b9a3..7231a7c 100755
--- a/build/debian/build.sh
+++ b/build/debian/build.sh
@@ -57,11 +57,10 @@
 
 prepare_build_id() {
 	local filename=build_id
-	local file=${workdir}/${filename}
 	if [ -z "${KOKORO_BUILD_NUMBER}" ]; then
-		echo eng-$(hostname)-$(date --utc) > ${file}
+		echo eng-$(hostname)-$(date --utc) > ${filename}
 	else
-		echo ${KOKORO_BUILD_NUMBER} > ${file}
+		echo ${KOKORO_BUILD_NUMBER} > ${filename}
 	fi
 	echo ${filename}
 }