diff --git a/README.md b/README.md
index 62752ef5..9d463ae2 100644
--- a/README.md
+++ b/README.md
@@ -87,7 +87,7 @@ Contributors
 Hacking
 -------
 
-Execute `./build.rb` or `./build.py` to effectively concatenate `main.js` with all the files in `code/`. It generates the user script which may be installed into your browser. Do not modify `total-conversion-build.user.js` manually, because it is automatically generated. Please don’t include it in patches either, because it makes merging harder. Instead, modify the files in `code/` and have that file built for you.
+Execute `./build.py` to effectively concatenate `main.js` with all the files in `code/`. It generates the user script which may be installed into your browser. Do not modify `total-conversion-build.user.js` manually, because it is automatically generated. Please don’t include it in patches either, because it makes merging harder. Instead, modify the files in `code/` and have that file built for you.
 
 `style.css` contains most styles required for the user-script. The extra ones can be found in `code/boot.js#window.setupStyles`. Only CSS rules that depend on config variables should be defined there.
 
diff --git a/autobuild.sh b/autobuild.sh
index df151d1a..1730aadd 100755
--- a/autobuild.sh
+++ b/autobuild.sh
@@ -1,8 +1,8 @@
 #!/bin/sh
 
-./build.rb
+./build.py
 FORMAT=$(echo "\033[1;33m%w%f\033[0m written")
 while inotifywait -qre close_write --exclude "total-conversion-build.user.js|.git*" --format "$FORMAT" .
 do
-  ./build.rb
+  ./build.py
 done
diff --git a/build.py b/build.py
old mode 100644
new mode 100755
diff --git a/build.rb b/build.rb
deleted file mode 100755
index 81789aea..00000000
--- a/build.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
-
-c = Dir.glob('code/*').map { |f| File.read(f) }
-n = Time.now.strftime('%Y-%m-%d-%H%M%S')
-m = File.read('main.js').gsub('@@BUILDDATE@@', n)
-m = m.split('@@INJECTHERE@@')
-t = m.insert(1, c).flatten.join("\n\n")
-File.open('total-conversion-build.user.js', 'w') {|f| f.write(t) }