diff --git a/CHANGELOG.md b/CHANGELOG.md
index 111fcbd..59bb882 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# v6.21.0
+- [#548](https://github.com/xmrig/xmrig-proxy/pull/548) Sync changes with XMRig.
+- [#553](https://github.com/xmrig/xmrig-proxy/pull/553) Fixes for **Zephyr** solo mining.
+
 # v6.20.0
 - [#538](https://github.com/xmrig/xmrig-proxy/pull/538) Added [Zephyr](https://www.zephyrprotocol.com/) coin support for solo mining.
 
diff --git a/src/version.h b/src/version.h
index 2265e67..5c90ffc 100644
--- a/src/version.h
+++ b/src/version.h
@@ -22,15 +22,15 @@
 #define APP_ID        "xmrig-proxy"
 #define APP_NAME      "xmrig-proxy"
 #define APP_DESC      "XMRig Stratum proxy"
-#define APP_VERSION   "6.20.1-dev"
+#define APP_VERSION   "6.21.0-dev"
 #define APP_DOMAIN    "xmrig.com"
 #define APP_SITE      "www.xmrig.com"
 #define APP_COPYRIGHT "Copyright (C) 2016-2023 xmrig.com"
 #define APP_KIND      "proxy"
 
 #define APP_VER_MAJOR  6
-#define APP_VER_MINOR  20
-#define APP_VER_PATCH  1
+#define APP_VER_MINOR  21
+#define APP_VER_PATCH  0
 
 #ifdef _MSC_VER
 #   if (_MSC_VER >= 1930)