diff --git a/pkgs/development/libraries/botan/unstable.nix b/pkgs/development/libraries/botan/unstable.nix
index 4e004da3217..170e7a75749 100644
--- a/pkgs/development/libraries/botan/unstable.nix
+++ b/pkgs/development/libraries/botan/unstable.nix
@@ -2,8 +2,8 @@
 
 callPackage ./generic.nix (args // {
   baseVersion = "1.11";
-  revision = "30";
-  sha256 = "09d1cvg6dnfi225wipc1fw691bq7xxdcmgkq8smldc5kivf3mbwd";
+  revision = "31";
+  sha256 = "1vnx75g5zzzbgsrwnmnhqdal29gcn63g0ldyj0g9cky8ha8iqx8f";
   openssl = null;
   postPatch = "sed '1i#include <cmath>' -i src/tests/test_bigint.cpp";
 })