diff --git a/pkgs/by-name/gl/glslviewer/package.nix b/pkgs/by-name/gl/glslviewer/package.nix
index cc43264d1093..71b4724cd8a3 100644
--- a/pkgs/by-name/gl/glslviewer/package.nix
+++ b/pkgs/by-name/gl/glslviewer/package.nix
@@ -42,6 +42,7 @@ stdenv.mkDerivation rec {
     ffmpeg
   ];
 
+  cmakeFlags = [ "-DCMAKE_POLICY_VERSION_MINIMUM=3.20" ];
   meta = with lib; {
     description = "Live GLSL coding renderer";
     homepage = "https://patriciogonzalezvivo.com/2015/glslViewer/";