diff --git a/src/check b/src/check
index b1a3b38..d66a2ef 100755
--- a/src/check
+++ b/src/check
@@ -4,4 +4,8 @@ set -eu
 
 [ -e /opt/resource/common ] && cd /opt/resource
 . ./common
-jq -r --null-input --arg version "$(crane digest "$REPOSITORY:$TAG")" '[{"digest": $version}] | tostring'
+
+filter='[
+  {"digest": $version}
+] | tostring'
+jq -r --null-input --arg version "$(crane digest "$REPOSITORY:$TAG")" "$filter"
diff --git a/src/in b/src/in
index bdb8e5f..211ceff 100755
--- a/src/in
+++ b/src/in
@@ -11,4 +11,7 @@ cd "$oci_dir"
 tar cf "$1/image.tar" ./*
 cd - 1>&2 2>/dev/null
 
-jq -r '.version | tostring' < "$INPUT_FILE"
+filter='{
+  "version": .version
+} | tostring'
+jq -r "$filter" < "$INPUT_FILE"
diff --git a/src/out b/src/out
index 937843c..95be4c2 100755
--- a/src/out
+++ b/src/out
@@ -11,4 +11,8 @@ cd "$oci_dir"
 tar xf "$1/$(jq -r .params.image < "$INPUT_FILE")"
 cd - 1>&2 2>/dev/null
 crane push "$oci_dir" "$REPOSITORY:$TAG" --image-refs="$IMAGE_REFS_FILE"
-jq -r --null-input --arg version "$(sed 's/^[^@]*@//' < "$IMAGE_REFS_FILE")" '{"digest": $version} | tostring'
+
+filter='{
+  "version": {"digest": $version}
+} | tostring'
+jq -r --null-input --arg version "$(sed 's/^[^@]*@//' < "$IMAGE_REFS_FILE")" "$filter"