diff --git a/pkgs/by-name/cy/cyan/package.nix b/pkgs/by-name/cy/cyan/package.nix
index 327994945850..7e3714a12476 100644
--- a/pkgs/by-name/cy/cyan/package.nix
+++ b/pkgs/by-name/cy/cyan/package.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch2,
   qt5,
   cmake,
   pkg-config,
@@ -20,6 +21,16 @@ stdenv.mkDerivation rec {
     hash = "sha256-R5sj8AN7UT9OIeUPNrdTIUQvtEitXp1A32l/Z2qRS94=";
   };
 
+  patches = [
+    # cmake-4 build fix:
+    #   https://github.com/rodlie/cyan/pull/123
+    (fetchpatch2 {
+      name = "cmake-4.patch";
+      url = "https://github.com/rodlie/cyan/commit/885e81310de8df7f32a5e1d2c722f89bcd969cd1.patch?full_index=1";
+      hash = "sha256-5VhXKamDNGeEvi86l+R3Lvzb4G5JFBq2dqqd6TdyxZ4=";
+    })
+  ];
+
   nativeBuildInputs = [
     cmake
     pkg-config