diff --git a/pkgs/development/compilers/ats/default.nix b/pkgs/development/compilers/ats/default.nix
index 6f15c0599ef..18fe0ffe204 100644
--- a/pkgs/development/compilers/ats/default.nix
+++ b/pkgs/development/compilers/ats/default.nix
@@ -17,7 +17,9 @@ stdenv.mkDerivation rec {
     description = "Functional programming language with dependent types";
     homepage    = "http://www.ats-lang.org";
     license     = stdenv.lib.licenses.gpl3Plus;
-    platforms   = stdenv.lib.platforms.unix;
+    # TODO: it looks like ATS requires gcc specifically. Someone with more knowledge
+    # will need to experiment.
+    platforms   = stdenv.lib.platforms.linux;
     maintainers = [ stdenv.lib.maintainers.thoughtpolice ];
   };
 }
diff --git a/pkgs/development/compilers/ats2/default.nix b/pkgs/development/compilers/ats2/default.nix
index 65f77ee8d3c..18f23416e80 100644
--- a/pkgs/development/compilers/ats2/default.nix
+++ b/pkgs/development/compilers/ats2/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
     description = "Functional programming language with dependent types";
     homepage    = "http://www.ats-lang.org";
     license     = stdenv.lib.licenses.gpl3Plus;
-    platforms   = stdenv.lib.platforms.unix;
+    platforms   = stdenv.lib.platforms.linux;
     maintainers = [ stdenv.lib.maintainers.thoughtpolice ];
   };
 }