diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfd2d2477c..374ed8be37 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## 31.0.0
 
+* `Core`:
+    * **THIS IS BREAKING CHANGE** All media files with sizes changed type of `fileSize` field from `Long` to `FileSize` (value class)
+
 ## 30.0.2
 
 * `Version`:
diff --git a/gradle.properties b/gradle.properties
index 67efefc681..f2dc6a3c72 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,4 +6,4 @@ kotlin.incremental=true
 kotlin.incremental.js=true
 
 library_group=dev.inmo
-library_version=31.0.0-t8
+library_version=31.0.0