diff --git a/changelog.txt b/changelog.txt
index 86da338f..da15b616 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -4988,3 +4988,7 @@ Mostly embedding-related improvements:
 - Fixed a bug which caused the screen to disappear on switch-to-fpp
 - Fixed the movement in Nil geometry
 - Fixed a crash when changing sight range while in rug
+
+2023-09-15 07:48 Update 12.1t
+- fixed a crash on projection changing
+- two new land structure options: horodisk and ideal Voronoi
diff --git a/hyper.h b/hyper.h
index 70754a32..c3697016 100644
--- a/hyper.h
+++ b/hyper.h
@@ -13,8 +13,8 @@
 #define _HYPER_H_
 
 // version numbers
-#define VER "12.1s"
-#define VERNUM_HEX 0xA933
+#define VER "12.1t"
+#define VERNUM_HEX 0xA934
 
 #include "sysconfig.h"