diff --git a/src/Library/Usage.php b/src/Library/Usage.php
index <HASH>..<HASH> 100644
--- a/src/Library/Usage.php
+++ b/src/Library/Usage.php
@@ -36,7 +36,7 @@ class Usage {
 	 * @access private
 	 * @var string
 	 */
-	private $gaId = 'UA-1501988-42';
+	private $gaId;
 
 	/**
 	 * An array of page prefixes to load usage tracking on.
@@ -60,6 +60,8 @@ class Usage {
 			Filter::add( $this );
 			self::$filtersAdded = true;
 		}
+
+		$this->gaId = Configs::get( 'gaId' );
 	}
 
 	/**
diff --git a/src/library.global.php b/src/library.global.php
index <HASH>..<HASH> 100644
--- a/src/library.global.php
+++ b/src/library.global.php
@@ -136,4 +136,8 @@ return array(
 			'priority'  => 'core',
 		),
 	),
+
+
+	// Google Analytics ID, used by the Usage class.
+	'gaId' => 'UA-1501988-42',
 );
Move ga id to config file