diff --git a/theme/upgrade.txt b/theme/upgrade.txt
index 25e137506bd..4da7f44f47e 100644
--- a/theme/upgrade.txt
+++ b/theme/upgrade.txt
@@ -1,7 +1,7 @@
 This files describes API changes in /theme/* themes,
 information provided here is intended especially for theme designer.
 
-=== 2.6 ===
+=== 2.5.1 ===
 
 Notes:
 * Block drag and drop functionality has been improved so that it works regardless of what block regions you use