diff --git a/_build_npm.ts b/_build_npm.ts
index 3f9b74f..48563eb 100755
--- a/_build_npm.ts
+++ b/_build_npm.ts
@@ -13,7 +13,14 @@ async function start() {
   await emptyDir("./npm");
 
   await build({
-    entryPoints: ["./mod.ts"],
+    entryPoints: [
+      "./mod.ts",
+      {
+        kind: "bin",
+        name: "is-bun",
+        path: "./cli.ts",
+      },
+    ],
     outDir: "./npm",
     shims: {},
     test: false,
diff --git a/cli.ts b/cli.ts
new file mode 100644
index 0000000..ac214ab
--- /dev/null
+++ b/cli.ts
@@ -0,0 +1,3 @@
+import { printIsBun } from "./mod.ts";
+
+printIsBun();
diff --git a/mod.ts b/mod.ts
index addf7ef..c8d4b0f 100644
--- a/mod.ts
+++ b/mod.ts
@@ -3,3 +3,11 @@ export function isBun(): boolean {
   // @ts-ignore
   return typeof Bun !== "undefined";
 }
+
+export function printIsBun() {
+  if (isBun()) {
+    console.log("Buntime runtime!");
+  } else {
+    console.log("It's not Bun, hun.");
+  }
+}