diff --git a/RELEASE-NOTES.md b/RELEASE-NOTES.md
index e672aa510..b522d8630 100644
--- a/RELEASE-NOTES.md
+++ b/RELEASE-NOTES.md
@@ -1,5 +1,9 @@
 # Release notes
 
+## [4.12.1] - 2025-01-03
+### Fixed
+- engine: heuristics for reconnecting cells in constructors improved (yields less defective offspring)
+
 ## [4.12.0] - 2024-12-29
 ### Added
 - gui/simulation parameters: overview widget for all parameter zones and radiation sources
diff --git a/source/Base/Resources.h b/source/Base/Resources.h
index 98dc79145..c8e1f1bc3 100644
--- a/source/Base/Resources.h
+++ b/source/Base/Resources.h
@@ -4,7 +4,7 @@
 
 namespace Const
 {
-    std::string const ProgramVersion = "4.12.0";
+    std::string const ProgramVersion = "4.12.1";
     std::string const DiscordURL = "https://discord.gg/7bjyZdXXQ2";
     std::string const AlienURL = "alien-project.org";
 
diff --git a/vcpkg.json b/vcpkg.json
index 4ea41a9bf..fcc0adf8d 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -1,6 +1,6 @@
 {
   "name": "alien",
-  "version": "4.12.0",
+  "version": "4.12.1",
   "dependencies": [
     {
       "name": "glew",