diff --git a/js/src/devtools/gc-ubench/benchmarks/globalArrayFgFinalized.js b/js/src/devtools/gc-ubench/benchmarks/globalArrayFgFinalized.js
new file mode 100644
index 000000000000..f2f9143762a3
--- /dev/null
+++ b/js/src/devtools/gc-ubench/benchmarks/globalArrayFgFinalized.js
@@ -0,0 +1,23 @@
+window.tests.set('globalArrayFgFinalized', (function() {
+var garbage = [];
+var garbageIndex = 0;
+return {
+    description: "var foo = [ new Map, new Map, ... ]; # (foreground finalized)",
+
+    load: (N) => { garbage = new Array(N); },
+    unload: () => { garbage = []; garbageIndex = 0; },
+
+    defaultGarbageTotal: "8K",
+    defaultGarbagePerFrame: "1M",
+
+    makeGarbage: (N) => {
+        var arr = [];
+        for (var i = 0; i < N; i++) {
+            arr.push(new Map);
+        }
+        garbage[garbageIndex++] = arr;
+        if (garbageIndex == garbage.length)
+            garbageIndex = 0;
+    }
+};
+})());
diff --git a/js/src/devtools/gc-ubench/index.html b/js/src/devtools/gc-ubench/index.html
index 9fdbf43f3c39..cc0de0a92ff9 100644
--- a/js/src/devtools/gc-ubench/index.html
+++ b/js/src/devtools/gc-ubench/index.html
@@ -13,6 +13,7 @@
   <script src="benchmarks/globalArrayObjectLiteral.js"></script>
   <script src="benchmarks/globalArrayReallocArray.js"></script>
   <script src="benchmarks/globalArrayBuffer.js"></script>
+  <script src="benchmarks/globalArrayFgFinalized.js"></script>
   <script src="benchmarks/selfCyclicWeakMap.js"></script>
   <script src="benchmarks/pairCyclicWeakMap.js"></script>
   <script src="benchmarks/textNodes.js"></script>