diff --git a/pkgs/development/libraries/mpir/default.nix b/pkgs/development/libraries/mpir/default.nix
index cbcf83f1d322..b9b25e7f43b3 100644
--- a/pkgs/development/libraries/mpir/default.nix
+++ b/pkgs/development/libraries/mpir/default.nix
@@ -11,6 +11,8 @@ stdenv.mkDerivation rec {
     sha256 = "1fvmhrqdjs925hzr2i8bszm50h00gwsh17p2kn2pi51zrxck9xjj";
   };
 
+  configureFlags = [ "--enable-cxx" ];
+
   meta = {
     inherit version;
     description = ''A highly optimised library for bignum arithmetic forked from GMP'';