diff --git a/packages/vocab/deno.json b/packages/vocab/deno.json
index a7afbdb3..73dd5120 100644
--- a/packages/vocab/deno.json
+++ b/packages/vocab/deno.json
@@ -25,7 +25,7 @@
   ],
   "tasks": {
     "check": "deno fmt --check && deno lint && deno check src/*.ts",
-    "compile": "deno run --allow-read --allow-write --allow-env --check scripts/codegen.ts && deno fmt src/vocab.ts && deno cache src/vocab.ts && deno check src/vocab.ts",
+    "compile": "deno run --allow-read --allow-write --allow-env --allow-run --check scripts/codegen.ts && deno cache src/vocab.ts && deno check src/vocab.ts",
     "test": "deno test --allow-read --allow-write --allow-env --unstable-kv --trace-leaks --parallel"
   }
 }
diff --git a/packages/vocab/scripts/codegen.ts b/packages/vocab/scripts/codegen.ts
index 9a178a88..02038c9b 100644
--- a/packages/vocab/scripts/codegen.ts
+++ b/packages/vocab/scripts/codegen.ts
@@ -2,6 +2,18 @@ import { generateVocab } from "@fedify/vocab-tools";
 import { rename } from "node:fs/promises";
 import { dirname, join } from "node:path";
 
+async function formatFile(filePath: string): Promise<void> {
+  const command = new Deno.Command("deno", {
+    args: ["fmt", filePath],
+    stderr: "piped",
+  });
+  const { code, stderr } = await command.output();
+  if (code !== 0) {
+    const errorOutput = new TextDecoder().decode(stderr);
+    throw new Error(`deno fmt failed with exit code ${code}: ${errorOutput}`);
+  }
+}
+
 async function codegen() {
   const scriptsDir = import.meta.dirname;
   if (!scriptsDir) {
@@ -12,6 +24,7 @@ async function codegen() {
   const realPath = join(schemaDir, "vocab.ts");
 
   await generateVocab(schemaDir, generatedPath);
+  await formatFile(generatedPath);
   await rename(generatedPath, realPath);
 }