diff --git a/pkgs/by-name/so/solvespace/package.nix b/pkgs/by-name/so/solvespace/package.nix
index 7db3f17c387f..92b397f8d071 100644
--- a/pkgs/by-name/so/solvespace/package.nix
+++ b/pkgs/by-name/so/solvespace/package.nix
@@ -90,7 +90,11 @@ stdenv.mkDerivation rec {
     EOF
   '';
 
-  cmakeFlags = [ "-DENABLE_OPENMP=ON" ];
+  cmakeFlags = [
+    "-DENABLE_OPENMP=ON"
+    # CMake 4 needs a minimum version
+    "-DCMAKE_POLICY_VERSION_MINIMUM=3.5"
+  ];
 
   meta = {
     description = "Parametric 3d CAD program";