diff --git a/lib/systems/doubles.nix b/lib/systems/doubles.nix
index 59bb095a28f5..96e602d0e167 100644
--- a/lib/systems/doubles.nix
+++ b/lib/systems/doubles.nix
@@ -48,6 +48,7 @@ in {
   mips    = filterDoubles predicates.isMips;
   riscv   = filterDoubles predicates.isRiscV;
   vc4     = filterDoubles predicates.isVc4;
+  js      = filterDoubles predicates.isJavaScript;
 
   cygwin  = filterDoubles predicates.isCygwin;
   darwin  = filterDoubles predicates.isDarwin;
diff --git a/lib/tests/systems.nix b/lib/tests/systems.nix
index 818749442f9f..6f52912994df 100644
--- a/lib/tests/systems.nix
+++ b/lib/tests/systems.nix
@@ -12,7 +12,7 @@ let
     expected = lib.sort lib.lessThan y;
   };
 in with lib.systems.doubles; lib.runTests {
-  testall = mseteq all (linux ++ darwin ++ freebsd ++ openbsd ++ netbsd ++ illumos ++ wasi ++ windows ++ embedded);
+  testall = mseteq all (linux ++ darwin ++ freebsd ++ openbsd ++ netbsd ++ illumos ++ wasi ++ windows ++ embedded ++ js);
 
   testarm = mseteq arm [ "armv5tel-linux" "armv6l-linux" "armv7a-linux" "armv7l-linux" "arm-none" "armv7a-darwin" ];
   testi686 = mseteq i686 [ "i686-linux" "i686-freebsd" "i686-netbsd" "i686-openbsd" "i686-cygwin" "i686-windows" "i686-none" "i686-darwin" ];