diff --git a/code/ulab.c b/code/ulab.c
index af7ba0ba..5c5067bd 100644
--- a/code/ulab.c
+++ b/code/ulab.c
@@ -33,7 +33,7 @@
 #include "user/user.h"
 #include "utils/utils.h"
 
-#define ULAB_VERSION 6.4.1
+#define ULAB_VERSION 6.4.2
 #define xstr(s) str(s)
 #define str(s) #s
 
diff --git a/docs/ulab-change-log.md b/docs/ulab-change-log.md
index ff921249..4d389f9a 100644
--- a/docs/ulab-change-log.md
+++ b/docs/ulab-change-log.md
@@ -1,3 +1,9 @@
+Thu, 11 Dec 2023
+
+version 6.4.2
+
+    fix upcasting with two uint8 operands (#650)
+
 Thu, 10 Aug 2023
 
 version 6.4.1