diff --git a/UPGRADE.md b/UPGRADE.md
index 2195f5b82..b71e10adb 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -2,7 +2,7 @@
 
 ## Minor BC BREAK: query cache key time is now a float
 
-As of 2.5, the `QueryCacheEntry#time` property will contain a float value
+As of 2.5.5, the `QueryCacheEntry#time` property will contain a float value
 instead of an integer in order to have more precision and also to be consistent
 with the `TimestampCacheEntry#time`.