diff --git a/Dart/benchmark.js b/Dart/benchmark.js
index ae7154c0..2ad4d3ab 100644
--- a/Dart/benchmark.js
+++ b/Dart/benchmark.js
@@ -62,8 +62,7 @@ function addTaskQueue(self) {
       ms = Math.max(0, ms);
       var id = timerIdCounter++;
       // A callback can be scheduled at most once.
-      // (console.assert is only available on D8)
-      // if (isD8) console.assert(f.$timerId === undefined);
+      console.assert(f.$timerId === undefined);
       f.$timerId = id;
       timerIds[id] = f;
       if (ms == 0 && !isNextTimerDue()) {
diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index d1ef7964..2a72a794 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -139,14 +139,8 @@ if (isInBrowser) {
     };
 }
 
-function assert(b, m = "") {
-    if (!b)
-        throw new Error(`Bad assertion: ${m}`);
-}
-
-
 function mean(values) {
-    assert(values instanceof Array);
+    console.assert(values instanceof Array);
     let sum = 0;
     for (let x of values)
         sum += x;
@@ -154,13 +148,13 @@ function mean(values) {
 }
 
 function geomeanScore(values) {
-    assert(values instanceof Array);
+    console.assert(values instanceof Array);
     let product = 1;
     for (let x of values)
         product *= x;
     const score = product ** (1 / values.length);
     // Allow 0 for uninitialized subScores().
-    assert(score >= 0, `Got invalid score: ${score}`)
+    console.assert(score >= 0, `Got invalid score: ${score}`)
     return score;
 }
 
@@ -206,7 +200,7 @@ class ShellFileLoader {
     // Cache / memoize previously read files, because some workloads
     // share common code.
     load(url) {
-        assert(!isInBrowser);
+        console.assert(!isInBrowser);
         if (!globalThis.prefetchResources)
             return `load("${url}");`
 
@@ -230,7 +224,7 @@ class Driver {
         // 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);
-        assert(this.benchmarks.length, "No benchmarks selected");
+        console.assert(this.benchmarks.length, "No benchmarks selected");
         // TODO: Cleanup / remove / merge `blobDataCache` and `loadCache` vs.
         // the global `fileLoader` cache.
         this.blobDataCache = { };
@@ -290,7 +284,7 @@ class Driver {
         const allScores = [];
         for (const benchmark of this.benchmarks) {
             const score = benchmark.score;
-            assert(score > 0, `Invalid ${benchmark.name} score: ${score}`);
+            console.assert(score > 0, `Invalid ${benchmark.name} score: ${score}`);
             allScores.push(score);
         }
 
@@ -303,13 +297,13 @@ class Driver {
         for (const benchmark of this.benchmarks) {
             for (let [category, value] of Object.entries(benchmark.subScores())) {
                 const arr = categoryScores.get(category);
-                assert(value > 0, `Invalid ${benchmark.name} ${category} score: ${value}`);
+                console.assert(value > 0, `Invalid ${benchmark.name} ${category} score: ${value}`);
                 arr.push(value);
             }
         }
 
         const totalScore = geomeanScore(allScores);
-        assert(totalScore > 0, `Invalid total score: ${totalScore}`);
+        console.assert(totalScore > 0, `Invalid total score: ${totalScore}`);
 
         if (isInBrowser) {
             const summaryElement = document.getElementById("result-summary");
@@ -628,13 +622,7 @@ class ShellScripts extends Scripts {
         } else
             globalObject = runString("");
 
-        globalObject.console = {
-            log: globalObject.print,
-            warn: (e) => { print("Warn: " + e); },
-            error: (e) => { print("Error: " + e); },
-            debug: (e) => { print("Debug: " + e); },
-        };
-
+        globalObject.console = console;
         globalObject.self = globalObject;
         globalObject.top = {
             currentResolve,
@@ -653,7 +641,7 @@ class ShellScripts extends Scripts {
     }
 
     addWithURL(url) {
-        assert(false, "Should not reach here in CLI");
+        console.assert(false, "Should not reach here in CLI");
     }
 }
 
@@ -813,7 +801,7 @@ class Benchmark {
             scripts.add(prerunCode);
 
         if (!isInBrowser) {
-            assert(this.scripts && this.scripts.length === this.plan.files.length);
+            console.assert(this.scripts && this.scripts.length === this.plan.files.length);
             for (const text of this.scripts)
                 scripts.add(text);
         } else {
@@ -929,7 +917,7 @@ class Benchmark {
     }
 
     prefetchResourcesForBrowser() {
-        assert(isInBrowser);
+        console.assert(isInBrowser);
 
         const promises = this.plan.files.map((file) => this.loadBlob("file", null, file).then((blobData) => {
                 if (!globalThis.allIsGood)
@@ -962,7 +950,7 @@ class Benchmark {
     }
 
     async retryPrefetchResource(type, prop, file) {
-        assert(isInBrowser);
+        console.assert(isInBrowser);
 
         const counter = JetStream.counter;
         const blobData = JetStream.blobDataCache[file];
@@ -998,7 +986,7 @@ class Benchmark {
     }
 
     async retryPrefetchResourcesForBrowser() {
-        assert(isInBrowser);
+        console.assert(isInBrowser);
 
         const counter = JetStream.counter;
         for (const resource of this.plan.files) {
@@ -1019,12 +1007,12 @@ class Benchmark {
     }
 
     prefetchResourcesForShell() {
-        assert(!isInBrowser);
+        console.assert(!isInBrowser);
 
-        assert(this.scripts === null, "This initialization should be called only once.");
+        console.assert(this.scripts === null, "This initialization should be called only once.");
         this.scripts = this.plan.files.map(file => shellFileLoader.load(file));
 
-        assert(this.preloads === null, "This initialization should be called only once.");
+        console.assert(this.preloads === null, "This initialization should be called only once.");
         this.preloads = Object.entries(this.plan.preload ?? {});
     }
 
@@ -1137,7 +1125,7 @@ class DefaultBenchmark extends Benchmark {
         this.averageTime = null;
         this.averageScore = null;
 
-        assert(this.iterations > this.worstCaseCount);
+        console.assert(this.iterations > this.worstCaseCount);
     }
 
     processResults(results) {
@@ -1149,7 +1137,7 @@ class DefaultBenchmark extends Benchmark {
         results = results.slice(1);
         results.sort((a, b) => a < b ? 1 : -1);
         for (let i = 0; i + 1 < results.length; ++i)
-            assert(results[i] >= results[i + 1]);
+            console.assert(results[i] >= results[i + 1]);
 
         const worstCase = [];
         for (let i = 0; i < this.worstCaseCount; ++i)
diff --git a/shell-config.js b/shell-config.js
index 8b29c7bf..8b2c6da9 100644
--- a/shell-config.js
+++ b/shell-config.js
@@ -24,11 +24,22 @@
 */
 
 const isInBrowser = false;
-console = {
-    log: globalThis?.console?.log ?? print,
-    error: globalThis?.console?.error ?? print,
-    warn: globalThis?.console?.warn ?? print,
-}
+if (typeof console == "undefined")
+    console = {};
+
+console.debug ??= (...args) => console.log("Debug:", ...args);
+console.log ??= (...args) => print(args.join(" "));
+console.warn ??= (...args) => console.log("Warn:", ...args);
+console.error ??= (...args) => console.log("Error:", ...args); 
+console.assert ??=  (condition, message) => {
+    if (!condition)
+        throw new Error(`Assertion failed: ${message}`);
+};
+console.trace ??= () => {
+    const targetObject = {};
+    Error.captureStackTrace(targetObject);
+    console.log(targetObject.stack);
+};
 
 const isD8 = typeof Realm !== "undefined";
 if (isD8)
@@ -43,4 +54,4 @@ if (typeof performance == "undefined")
     performance = {};
 
 performance.mark ??= function(){};
-performance.measure ??= function(){};
\ No newline at end of file
+performance.measure ??= function(){};