diff --git a/pkgs/development/libraries/pcmsolver/default.nix b/pkgs/development/libraries/pcmsolver/default.nix
index dd94a4a088cb..a957d517bf7a 100644
--- a/pkgs/development/libraries/pcmsolver/default.nix
+++ b/pkgs/development/libraries/pcmsolver/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, cmake, perl, gfortran, python2
+{ lib, stdenv, fetchFromGitHub, cmake, perl, gfortran, python3
 , boost, eigen, zlib
 } :
 
@@ -13,11 +13,18 @@ stdenv.mkDerivation rec {
     sha256= "0jrxr8z21hjy7ik999hna9rdqy221kbkl3qkb06xw7g80rc9x9yr";
   };
 
+  # Glibc 2.34 changed SIGSTKSZ to a dynamic value, which breaks
+  # PCMsolver. Replace SIGSTKZ by the backward-compatible _SC_SIGSTKSZ.
+  postPatch = ''
+    substituteInPlace external/Catch/catch.hpp \
+      --replace SIGSTKSZ _SC_SIGSTKSZ
+  '';
+
   nativeBuildInputs = [
     cmake
     gfortran
     perl
-    python2
+    python3
   ];
 
   buildInputs = [