diff --git a/pkgs/by-name/cm/cmark-gfm/package.nix b/pkgs/by-name/cm/cmark-gfm/package.nix
index 645a7aabfbce..1ea91aaa9751 100644
--- a/pkgs/by-name/cm/cmark-gfm/package.nix
+++ b/pkgs/by-name/cm/cmark-gfm/package.nix
@@ -15,6 +15,13 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-HiSGtRsSbW03R6aKoMVVFOLrwP5aXtpeXUC/bE5M/qo=";
   };
 
+  # Fix the build with CMake 4.
+  postPatch = ''
+    substituteInPlace CMakeLists.txt --replace-fail \
+      "cmake_minimum_required(VERSION 3.0)" \
+      "cmake_minimum_required(VERSION 3.13)"
+  '';
+
   nativeBuildInputs = [ cmake ];
 
   doCheck = true;