diff --git a/main.mjs b/main.mjs
index 4810805..0b89e7a 100644
--- a/main.mjs
+++ b/main.mjs
@@ -17,6 +17,8 @@ function exit(message) {
 }
 
 async function main() {
+  core.warning("Running on setup-deno@1, which is deprecated.\nPlease update to setup-deno@2, which defaults to Deno 2.0");
+
   try {
     const denoVersionFile = core.getInput("deno-version-file");
     const range = parseVersionRange(
diff --git a/package.json b/package.json
index cdeb698..0cb4034 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "setup-deno",
   "description": "Set up Deno easially in GitHub Actions",
-  "version": "1.5.1",
+  "version": "1.5.2",
   "author": "Deno Land Inc",
   "license": "MIT",
   "type": "module",