diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 84cdd5cd..7a4e2d4e 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -201,11 +201,13 @@ const fileLoader = (function() {
 })();
 
 class Driver {
-    constructor() {
+    constructor(benchmarks) {
         this.isReady = false;
         this.isDone = false;
         this.errors = [];
-        this.benchmarks = new Set();
+        // Make benchmark list unique and sort it.
+        this.benchmarks = Array.from(new Set(benchmarks));
+        this.benchmarks.sort((a, b) => a.plan.name.toLowerCase() < b.plan.name.toLowerCase() ? 1 : -1);
         // TODO: Cleanup / remove / merge `blobDataCache` and `loadCache` vs.
         // the global `fileLoader` cache.
         this.blobDataCache = { };
@@ -216,36 +218,6 @@ class Driver {
         this.counter.failedPreloadResources = 0;
     }
 
-    enableBenchmark(benchmark) {
-        // TODO: Remove, make `this.benchmarks` immutable and set it once in the
-        // ctor instead of this and the global `addBenchmarksBy*` functions.
-        this.benchmarks.add(benchmark);
-    }
-
-    enableBenchmarksByName(name) {
-        const benchmark = benchmarksByName.get(name.toLowerCase());
-
-        if (!benchmark)
-            throw new Error(`Couldn't find benchmark named "${name}"`);
-
-        this.enableBenchmark(benchmark);
-    }
-
-    enableBenchmarksByTag(tag, excludeTags) {
-        const benchmarks = benchmarksByTag.get(tag.toLowerCase());
-
-        if (!benchmarks) {
-            const validTags = Array.from(benchmarksByTag.keys()).join(", ");
-            throw new Error(`Couldn't find tag named: ${tag}.\n Choices are ${validTags}`);
-        }
-
-        for (const benchmark of benchmarks) {
-            if (excludeTags && benchmark.hasAnyTag(...excludeTags))
-                continue
-            this.enableBenchmark(benchmark);
-        }
-    }
-
     async start() {
         let statusElement = false;
         let summaryElement = false;
@@ -451,15 +423,9 @@ class Driver {
         });
     }
 
-    initializeBenchmarks() {
-        this.benchmarks = Array.from(this.benchmarks);
-        this.benchmarks.sort((a, b) => a.plan.name.toLowerCase() < b.plan.name.toLowerCase() ? 1 : -1);
-    }
-
     async initialize() {
         if (isInBrowser)
             window.addEventListener("error", (e) => this.pushError("driver startup", e.error));
-        this.initializeBenchmarks();
         await this.prefetchResources();
         this.prepareToRun();
         this.isReady = true;
@@ -2273,34 +2239,62 @@ for (const benchmark of BENCHMARKS) {
     }
 }
 
-this.JetStream = new Driver();
-
 
 function processTestList(testList)
 {
     let benchmarkNames = [];
+    let benchmarks = [];
 
     if (testList instanceof Array)
         benchmarkNames = testList;
     else
         benchmarkNames = testList.split(/[\s,]/);
 
-    for (let name of benchmarkNames) {
-        name = name.toLowerCase();
+    for (const name of benchmarkNames) {
         if (benchmarksByTag.has(name))
-            globalThis.JetStream.enableBenchmarksByTag(name);
+            benchmarks.push(...findBenchmarksByTag(name));
         else
-            globalThis.JetStream.enableBenchmarksByName(name);
+            benchmarks.push(findBenchmarkByName(name));
     }
+    return benchmarks;
+}
+
+
+function findBenchmarkByName(name) {
+    const benchmark = benchmarksByName.get(name.toLowerCase());
+
+    if (!benchmark)
+        throw new Error(`Couldn't find benchmark named "${name}"`);
+
+    return benchmark;
 }
 
+
+function findBenchmarksByTag(tag, excludeTags) {
+    let benchmarks = benchmarksByTag.get(tag.toLowerCase());
+    if (!benchmarks) {
+        const validTags = Array.from(benchmarksByTag.keys()).join(", ");
+        throw new Error(`Couldn't find tag named: ${tag}.\n Choices are ${validTags}`);
+    }
+    if (excludeTags) {
+        benchmarks = benchmarks.filter(benchmark => {
+            return !benchmark.hasAnyTag(...excludeTags);
+        });
+    }
+    return benchmarks;
+}
+
+
+let benchmarks = [];
 const defaultDisabledTags = [];
 // FIXME: add better support to run Worker tests in shells.
 if (!isInBrowser)
     defaultDisabledTags.push("WorkerTests");
 
 if (globalThis.testList?.length) {
-    processTestList(globalThis.testList);
+    benchmarks = processTestList(globalThis.testList);
 } else {
-    globalThis.JetStream.enableBenchmarksByTag("Default", defaultDisabledTags)
+    benchmarks = findBenchmarksByTag("Default", defaultDisabledTags)
 }
+
+this.JetStream = new Driver(benchmarks);
diff --git a/tests/unit-tests.js b/tests/unit-tests.js
index f8efd23a..bda9de98 100644
--- a/tests/unit-tests.js
+++ b/tests/unit-tests.js
@@ -38,10 +38,8 @@ function assertEquals(actual, expected, message) {
 
 
 (function testDriverBenchmarksOrder() {
-  const driver = new Driver();
-  driver.enableBenchmarksByTag("all");
-  assertEquals(driver.benchmarks.size, BENCHMARKS.length);
-  driver.initializeBenchmarks();
+  const benchmarks = findBenchmarksByTag("all");
+  const driver = new Driver(benchmarks);
   assertEquals(driver.benchmarks.length, BENCHMARKS.length);
   const names = driver.benchmarks.map(b => b.name.toLowerCase()).sort().reverse();
   for (let i = 0; i < names.length; i++) {
@@ -51,12 +49,10 @@ function assertEquals(actual, expected, message) {
 
 
 (function testEnableByTag() {
-  const driverA = new Driver();
-  const driverB = new Driver();
-  driverA.enableBenchmarksByTag("Default");
-  driverB.enableBenchmarksByTag("default");
-  assertTrue(driverA.benchmarks.size > 0);
-  assertEquals(driverA.benchmarks.size, driverB.benchmarks.size);
+  const driverA = new Driver(findBenchmarksByTag("Default"));
+  const driverB = new Driver(findBenchmarksByTag("default"));
+  assertTrue(driverA.benchmarks.length > 0);
+  assertEquals(driverA.benchmarks.length, driverB.benchmarks.length);
   const enabledBenchmarkNames = new Set(
       Array.from(driverA.benchmarks).map(b => b.name));
   for (const benchmark of BENCHMARKS) {
@@ -66,6 +62,16 @@ function assertEquals(actual, expected, message) {
 })();
 
 
+(function testDriverEnableDuplicateAndSort() {
+    const benchmarks = [...findBenchmarksByTag("wasm"), ...findBenchmarksByTag("wasm")];
+    assertTrue(benchmarks.length > 0);
+    const uniqueBenchmarks = new Set(benchmarks);
+    assertFalse(uniqueBenchmarks.size == benchmarks.length);
+    const driver = new Driver(benchmarks);
+    assertEquals(driver.benchmarks.length, uniqueBenchmarks.size);
+})();
+
+
 (function testBenchmarkSubScores() {
   for (const benchmark of BENCHMARKS) {
     const subScores = benchmark.subScores();