diff --git a/build.js b/build.js
index 59f201d..666a82e 100644
--- a/build.js
+++ b/build.js
@@ -5,6 +5,7 @@ const path = require('path');
 const util = require('util');
 const postcss = require('postcss');
 const htmlminify = require('html-minifier-terser').minify;
+const childProcess = require('child_process');
 const utils = require('./src/utils.js');
 const assproc = require('./src/assproc.js');
 
@@ -100,6 +101,14 @@ const htmlMinifyOptions = {
         FUTAMI_URL: config.common_url,
         MAMI_URL: config.modern_url,
         AMI_URL: config.compat_url,
+        GIT_HASH: await (() => {
+            return new Promise((resolve, reject) => {
+                childProcess.exec('git log --pretty="%H" -n1 HEAD', (err, stdout) => {
+                    if(err) reject(err);
+                    else resolve(stdout.trim());
+                });
+            });
+        })(),
     };
 
     console.log('Ensuring assets directory exists...');
diff --git a/src/assproc.js b/src/assproc.js
index 8fb7dec..bf457ca 100644
--- a/src/assproc.js
+++ b/src/assproc.js
@@ -59,7 +59,7 @@ exports.process = async function(root, options) {
                             const bvProps = [];
 
                             for(const bvName in options.buildVars)
-                                bvProps.push(`${bvName}: { value: ${JSON.stringify(options.buildVars[bvName])}, writable: false }`);
+                                bvProps.push(`${bvName}: { value: ${JSON.stringify(options.buildVars[bvName])} }`);
 
                             if(Object.keys(bvProps).length > 0)
                                 output += `Object.defineProperties(${bvTarget}, { ${bvProps.join(', ')} });\n`;