diff --git a/hack/Dockerfile-child b/hack/Dockerfile-child
index 428d9078..27e657e2 100644
--- a/hack/Dockerfile-child
+++ b/hack/Dockerfile-child
@@ -1,10 +1,11 @@
-FROM ovhcom/utask:DOCKER_TAG AS builder
+ARG UTASK_VERSION=DOCKER_TAG
+FROM ovhcom/utask:${UTASK_VERSION} AS builder
 
 COPY .  /go/src/github.com/ovh/utask
 WORKDIR /go/src/github.com/ovh/utask
 RUN make
 
-FROM ovhcom/utask:DOCKER_TAG
+FROM ovhcom/utask:${UTASK_VERSION}
 
 COPY templates  /app/templates
 COPY --from=builder /go/src/github.com/ovh/utask/plugins /app/plugins
diff --git a/hack/generate-install-script.sh b/hack/generate-install-script.sh
index 1f417d58..741eb3d6 100755
--- a/hack/generate-install-script.sh
+++ b/hack/generate-install-script.sh
@@ -11,7 +11,7 @@ fi
 version=`git describe --tags $(git rev-list --tags --max-count=1)`
 
 write_block() {
-    echo "cat <<EOF >$1" >> $dst
+    echo "cat <<'EOF' >$1" >> $dst
     sed "s/DOCKER_TAG/$version/" $2 >> $dst
     echo "EOF" >> $dst
     echo "" >> $dst
diff --git a/hack/template-schema.json b/hack/template-schema.json
index 72a1a89b..81eb17c7 100644
--- a/hack/template-schema.json
+++ b/hack/template-schema.json
@@ -73,6 +73,10 @@
                 "foreach": {
                     "type": "string",
                     "description": "Elements on which the step will loop"
+                },
+                "json_schema": {
+                    "type": "object",
+                    "description": "Elements on which the step will loop"
                 }
             }
         },