diff --git a/build/build.ts b/build/build.ts
index b3dc1f7..1ae3f65 100644
--- a/build/build.ts
+++ b/build/build.ts
@@ -2,6 +2,7 @@ import path from "node:path";
 import fs from "node:fs";
 import { createHash } from "node:crypto";
 import { promisify } from "node:util";
+import { exec } from "node:child_process";
 import * as esbuild from "esbuild";
 import { optimize } from "svgo";
 import * as xmlParser from "../lib/xml-parser.ts";
@@ -20,12 +21,9 @@ const fsAsync = {
   mkdir: promisify(fs.mkdir),
 };
 
-const MODE = process.env["NODE_ENV"] || "production";
+const execAsync = promisify(exec);
 
-const BUILD_METADATA = new Date()
-  .toISOString()
-  .split(".")[0]
-  .replace(/[^0-9]/g, "");
+const MODE = process.env["NODE_ENV"] || "production";
 
 const INPUT_DIR = process.cwd();
 const OUTPUT_DIR = path.join(INPUT_DIR, "dist");
@@ -140,17 +138,38 @@ function generateSymbol(id: string, svgStr: string): string {
   return `<symbol id="icon-${id}" ${viewBox}>${symbolBody}</symbol>`;
 }
 
+async function getBuildMetadata(): Promise<string> {
+  const date = new Date().toISOString().slice(2, 10).replaceAll("-", "");
+
+  const [commit, diff, newFiles] = await Promise.all([
+    execAsync("git rev-parse HEAD"),
+    execAsync("git diff HEAD"),
+    execAsync("git ls-files --others --exclude-standard"),
+  ]).then((res) => res.map((r) => r.stdout.trim()));
+
+  if (!diff && !newFiles) return date + commit.slice(0, 4);
+
+  const hash = createHash("md5");
+  hash.update(commit).update(diff).update(newFiles);
+  for (const file of newFiles.split("\n").filter((f) => f))
+    hash.update(await fsAsync.readFile(file));
+  return date + hash.digest("hex").slice(0, 4);
+}
+
 async function init(): Promise<void> {
-  const [packageJsonFile, npmShrinkwrapFile] = await Promise.all([
-    fsAsync.readFile(path.join(INPUT_DIR, "package.json")),
-    fsAsync.readFile(path.join(INPUT_DIR, "npm-shrinkwrap.json")),
-  ]);
+  const [buildMetadata, packageJsonFile, npmShrinkwrapFile] = await Promise.all(
+    [
+      getBuildMetadata(),
+      fsAsync.readFile(path.join(INPUT_DIR, "package.json")),
+      fsAsync.readFile(path.join(INPUT_DIR, "npm-shrinkwrap.json")),
+    ],
+  );
 
   const packageJson = JSON.parse(packageJsonFile.toString());
   delete packageJson["devDependencies"];
   delete packageJson["private"];
   delete packageJson["scripts"];
-  packageJson["version"] = `${packageJson["version"]}+${BUILD_METADATA}`;
+  packageJson["version"] = `${packageJson["version"]}+${buildMetadata}`;
 
   const npmShrinkwrap = JSON.parse(npmShrinkwrapFile.toString());
   npmShrinkwrap["version"] = packageJson["version"];