diff --git a/pkgs/development/tools/misc/gnum4/default.nix b/pkgs/development/tools/misc/gnum4/default.nix
index e5ea17841aa..12a5b8f2adc 100644
--- a/pkgs/development/tools/misc/gnum4/default.nix
+++ b/pkgs/development/tools/misc/gnum4/default.nix
@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
     '';
 
     license = stdenv.lib.licenses.gpl3Plus;
-    platforms = stdenv.lib.platforms.unix;
+    platforms = stdenv.lib.platforms.unix ++ stdenv.lib.platforms.windows;
   };
 
 }