diff --git a/scripts/postcss/css-compile-variables.js b/scripts/postcss/css-compile-variables.js
index 263fbe36..7152535e 100644
--- a/scripts/postcss/css-compile-variables.js
+++ b/scripts/postcss/css-compile-variables.js
@@ -104,10 +104,10 @@ function populateMapWithDerivedVariables(map, cssFileLocation) {
          */
         return;
     }
-    const derivedVariables = new Set([
+    const derivedVariables = [
         ...([...resolvedMap.keys()].filter(v => !aliasMap.has(v))),
         ...([...aliasMap.entries()].map(([alias, variable]) => `${alias}=${variable}`))
-    ]);
+    ];
     map.set(location, { "derived-variables": derivedVariables });
 }
 
diff --git a/scripts/postcss/test.js b/scripts/postcss/test.js
index d07f07e4..8d1412ea 100644
--- a/scripts/postcss/test.js
+++ b/scripts/postcss/test.js
@@ -131,9 +131,9 @@ module.exports.tests = function tests() {
                 color: var(--my-alias--lighter-15);
             }`;
             await postcss([plugin({ derive, compiledVariables })]).process(inputCSS, { from: "/foo/bar/test.css", });
-            const actualSet = compiledVariables.get("/foo/bar")["derived-variables"];
-            const expectedSet = new Set(["icon-color--darker-20", "my-alias=icon-color--darker-20", "my-alias--lighter-15"]);
-            assert.deepEqual(actualSet, expectedSet);
+            const actualArray = compiledVariables.get("/foo/bar")["derived-variables"];
+            const expectedArray = ["icon-color--darker-20", "my-alias=icon-color--darker-20", "my-alias--lighter-15"];
+            assert.deepStrictEqual(actualArray.sort(), expectedArray.sort());
         }
     };
 };