diff --git a/pkgs/tools/misc/gams/default.nix b/pkgs/tools/misc/gams/default.nix
index 990282b2d58..011231692f3 100644
--- a/pkgs/tools/misc/gams/default.nix
+++ b/pkgs/tools/misc/gams/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, unzip, file, licenseFile, optgamsFile}:
+{ stdenv, fetchurl, unzip, file, licenseFile ? null, optgamsFile ? null}:
 
 assert licenseFile != null;
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 22efa454676..73112b71d1f 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -674,10 +674,7 @@ in
 
   gamecube-tools = callPackage ../development/tools/gamecube-tools { };
 
-  gams = callPackage ../tools/misc/gams {
-    licenseFile = config.gams.licenseFile or null;
-    optgamsFile = config.gams.optgamsFile or null;
-  };
+  gams = callPackage ../tools/misc/gams (config.gams or {});
 
   git-fire = callPackage ../tools/misc/git-fire { };