diff --git a/pkgs/by-name/do/double-conversion/package.nix b/pkgs/by-name/do/double-conversion/package.nix
index 11e87a0546c0..a377165483f0 100644
--- a/pkgs/by-name/do/double-conversion/package.nix
+++ b/pkgs/by-name/do/double-conversion/package.nix
@@ -2,6 +2,7 @@
   stdenv,
   lib,
   fetchFromGitHub,
+  fetchpatch,
   cmake,
   enableStatic ? stdenv.hostPlatform.isStatic,
 }:
@@ -17,6 +18,20 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-M80H+azCzQYa4/gBLWv5GNNhEuHsH7LbJ/ajwmACnrM=";
   };
 
+  patches = [
+    # Fix the build with CMake 4.
+    (fetchpatch {
+      name = "double-conversion-fix-cmake-4-1.patch";
+      url = "https://github.com/google/double-conversion/commit/101e1ba89dc41ceb75090831da97c43a76cd2906.patch";
+      hash = "sha256-VRmuNXdzt/I+gWbz5mwWkx5IGn8Vsl9WkdwRsuwZdkU=";
+    })
+    (fetchpatch {
+      name = "double-conversion-fix-cmake-4-2.patch";
+      url = "https://github.com/google/double-conversion/commit/0604b4c18815aadcf7f4b78dfa6bfcb91a634ed7.patch";
+      hash = "sha256-cJBp1ou1O/bMQ/7kvcX52dWbUdhmPfQ9aWmEhQdyhis=";
+    })
+  ];
+
   nativeBuildInputs = [ cmake ];
 
   cmakeFlags = lib.optional (!enableStatic) "-DBUILD_SHARED_LIBS=ON";