diff --git a/pkgs/os-specific/linux/smem/default.nix b/pkgs/os-specific/linux/smem/default.nix
index a07eec431c3..ede8d425f12 100644
--- a/pkgs/os-specific/linux/smem/default.nix
+++ b/pkgs/os-specific/linux/smem/default.nix
@@ -29,5 +29,6 @@ stdenv.mkDerivation rec {
     description = "A memory usage reporting tool that takes shared memory into account";
     platforms = lib.platforms.linux;
     maintainers = [ lib.maintainers.eelco ];
+    license = lib.licenses.gpl2Plus;
   };
 }