diff --git a/Dockerfile b/Dockerfile
index f9e6783..eac45d9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,4 +6,6 @@ COPY . /opt/humans.txt
 
 RUN npm i --production
 
+ENV FORCE_COLOR=3
+
 ENTRYPOINT ["bash", "/opt/humans.txt/run.sh"]
diff --git a/action.js b/action.js
index ce5b66f..4aec587 100644
--- a/action.js
+++ b/action.js
@@ -13,7 +13,7 @@ const formatters = {
 main()
 
 function main() {
-  const format = process.argv[2] || (process.stdout.isTTY ? "shell" : "txt")
+  const format = process.argv[2] || ((process.env.GITHUB_ACTION || process.stdout.isTTY) ? "shell" : "txt")
 
   const formatter = formatters[format]
   if (!formatter) {