diff --git a/doc/03-cli.md b/doc/03-cli.md
index 88f2b335a..611fae4a2 100644
--- a/doc/03-cli.md
+++ b/doc/03-cli.md
@@ -461,6 +461,14 @@ This file allows you to set [configuration](04-schema.md#config) and
 In case global configuration matches _local_ configuration, the _local_
 configuration in the project's `composer.json` always wins.
 
+### COMPOSER_CACHE_DIR
+
+The `COMPOSER_CACHE_DIR` var allows you to change the composer cache directory,
+which is also configurable via the [`cache-dir`](04-schema.md#config) option.
+
+By default it points to $COMPOSER_HOME/cache on \*nix and OSX, and
+`C:\Users\<user>\AppData\Local\Composer` (or `%LOCALAPPDATA%/Composer`) on Windows.
+
 ### COMPOSER_PROCESS_TIMEOUT
 
 This env var controls the time composer waits for commands (such as git
diff --git a/src/Composer/Factory.php b/src/Composer/Factory.php
index e45c75001..441d3fd8a 100644
--- a/src/Composer/Factory.php
+++ b/src/Composer/Factory.php
@@ -60,7 +60,7 @@ class Factory
                 if ($cacheDir = getenv('LOCALAPPDATA')) {
                     $cacheDir .= '/Composer';
                 } else {
-                    $cacheDir = getenv('APPDATA') . '/Composer/cache';
+                    $cacheDir = $home . '/cache';
                 }
                 $cacheDir = strtr($cacheDir, '\\', '/');
             } else {