diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b430fb..b8169d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog][keepachangelog] and this project adheres to [Semantic Versioning][semver].
 
+## Unreleased
+
+### Added
+
+- GIBDD region code for `Sankt-Peterburg` - `778`
+
 ## v3.19.0
 
 ### Added
diff --git a/data/subject/codes.json b/data/subject/codes.json
index 7fb4b34..961e6be 100644
--- a/data/subject/codes.json
+++ b/data/subject/codes.json
@@ -694,7 +694,8 @@
             78,
             98,
             178,
-            198
+            198,
+            778
         ],
         "code_iso_31662": "RU-SPE"
     },