diff --git a/src/Composer/Composer.php b/src/Composer/Composer.php
index 80a3ea0c5..16f29f113 100644
--- a/src/Composer/Composer.php
+++ b/src/Composer/Composer.php
@@ -54,7 +54,7 @@ class Composer
     const VERSION = '@package_version@';
     const BRANCH_ALIAS_VERSION = '@package_branch_alias_version@';
     const RELEASE_DATE = '@release_date@';
-    const SOURCE_VERSION = '2.0.999-dev+source';
+    const SOURCE_VERSION = '2.1.999-dev+source';
 
     /**
      * Version number of the internal composer-runtime-api package