diff --git a/tools/buildx-gen.sh b/tools/buildx-gen.sh
index a64775ef1b6c..3c07c054218e 100755
--- a/tools/buildx-gen.sh
+++ b/tools/buildx-gen.sh
@@ -16,8 +16,9 @@
 
 set -eu
 
-# 
-DOCKER_PLATFORMS=${${DOCKER_PLATFORMS}:-"linux/amd64,linux/arm64,linux/arm/v7"}
+if [[ -z ${DOCKER_PLATFORMS} ]]; then
+    export DOCKER_PLATFORMS="linux/amd64,linux/arm64,linux/arm/v7"
+fi
 if ! docker buildx ls | grep -q container-builder; then
   docker buildx create --driver-opt network=host  --platform ${DOCKER_PLATFORMS} --name container-builder --use
 fi