diff --git a/script/linux-build-docker b/script/linux-build-docker
index 5505371eb..6d447221b 100755
--- a/script/linux-build-docker
+++ b/script/linux-build-docker
@@ -61,6 +61,8 @@ if [[ "${PLATFORM}" == "flex" ]]; then
   # Update the Dockerfile to use local deb image
   DIMG="endpoints-runtime.deb"
   sed -i -e "s|endpoints-runtime||" \
+      -e 's|ARG BASE_IMAGE_TAG=latest||' \
+      -e 's|${BASE_IMAGE_TAG}|latest|' \
       -e "s|EXPOSE 8080|\nADD ${DIMG} ${DIMG}\nRUN apt-get update --fix-missing -qq \&\& \\\ \n    apt-get install -qqy python \&\& \\\ \n    dpkg -i /${DIMG}\n&|" \
       "$FLEX_DIR/nginx_proxy/Dockerfile"
   DOCKERFILE_PATH="$FLEX_DIR/nginx_proxy"