diff --git a/BUILDS.md b/BUILDS.md
index 175fc96c..3e60fefd 100644
--- a/BUILDS.md
+++ b/BUILDS.md
@@ -3,7 +3,7 @@
 ## Prerequisites
 * 64-bit OS:
     - the go-rfc5322 module cannot currently be compiled for 32-bit OSes
-* Go 1.21.6
+* Go 1.21.9
 * Bash with basic build utils: make, gcc, sed, find, grep, ...
   - For Windows, it is recommended to use MinGW 64bit shell from [MSYS2](https://www.msys2.org/)
 * GCC (Linux), msvc (Windows) or Xcode (macOS)
diff --git a/go.mod b/go.mod
index 151c8a66..c3351eeb 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,8 @@ module github.com/ProtonMail/proton-bridge/v3
 
 go 1.21
 
+toolchain go1.21.9
+
 require (
 	github.com/0xAX/notificator v0.0.0-20220220101646-ee9b8921e557
 	github.com/Masterminds/semver/v3 v3.2.0