diff --git a/Makefile b/Makefile
index 6fa145e226..d01d4bf132 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 TS_FILES = \
+	console.ts \
 	deno.d.ts \
 	deno.ts \
 	dispatch.ts \
diff --git a/console.ts b/console.ts
new file mode 100644
index 0000000000..0d1585bc89
--- /dev/null
+++ b/console.ts
@@ -0,0 +1,123 @@
+const print = V8Worker2.print;
+
+// tslint:disable-next-line:no-any
+type ConsoleContext = Set<any>;
+
+// tslint:disable-next-line:no-any
+function getClassInstanceName(instance: any): string {
+  if (typeof instance !== "object") {
+    return "";
+  }
+  if (instance && instance.__proto__ && instance.__proto__.constructor) {
+    return instance.__proto__.constructor.name; // could be "Object" or "Array"
+  }
+  return "";
+}
+
+// tslint:disable-next-line:no-any
+function stringify(ctx: ConsoleContext, value: any): string {
+  switch (typeof value) {
+    case "string":
+      return value;
+    case "number":
+    case "boolean":
+    case "undefined":
+    case "symbol":
+      return String(value);
+    case "function":
+      if (value.name && value.name !== "anonymous") { // from MDN spec
+        return `[Function: ${value.name}]`;
+      }
+      return "[Function]";
+    case "object":
+      if (value === null) {
+        return "null";
+      }
+
+      if (ctx.has(value)) {
+        return "[Circular]";
+      }
+
+      ctx.add(value);
+      const entries: string[] = [];
+
+      if (Array.isArray(value)) {
+        for (const el of value) {
+          entries.push(stringify(ctx, el));
+        }
+
+        ctx.delete(value);
+
+        if (entries.length === 0) {
+          return "[]";
+        }
+        return `[ ${entries.join(", ")} ]`;
+      } else {
+        let baseString = "";
+
+        const className = getClassInstanceName(value);
+        let shouldShowClassName = false;
+        if (className && className !== "Object" && className !== "anonymous") {
+          shouldShowClassName = true;
+        }
+
+        for (const key of Object.keys(value)) {
+          entries.push(`${key}: ${stringify(ctx, value[key])}`);
+        }
+
+        ctx.delete(value);
+
+        if (entries.length === 0) {
+          baseString = "{}";
+        } else {
+          baseString = `{ ${entries.join(", ")} }`;
+        }
+
+        if (shouldShowClassName) {
+          baseString = `${className} ${baseString}`;
+        }
+
+        return baseString;
+      }
+    default:
+      return "[Not Implemented]";
+  }
+}
+
+// tslint:disable-next-line:no-any
+function stringifyArgs(args: any[]): string {
+  const out: string[] = [];
+  for (const a of args) {
+    if (typeof a === "string") {
+      out.push(a);
+    } else {
+      // tslint:disable-next-line:no-any
+      out.push(stringify(new Set<any>(), a));
+    }
+  }
+  return out.join(" ");
+}
+
+export class Console {
+  // tslint:disable-next-line:no-any
+  log(...args: any[]): void {
+    print(stringifyArgs(args));
+  }
+
+  debug = this.log;
+  info = this.log;
+
+  // tslint:disable-next-line:no-any
+  warn(...args: any[]): void {
+    print(`ERROR: ${stringifyArgs(args)}`);
+  }
+
+  error = this.warn;
+
+  // tslint:disable-next-line:no-any
+  assert(condition: boolean, ...args: any[]): void {
+    if (!condition) {
+      throw new Error(`Assertion failed: ${stringifyArgs(args)}`);
+    }
+  }
+}
diff --git a/globals.ts b/globals.ts
index 896c2a0eb3..cca72d172d 100644
--- a/globals.ts
+++ b/globals.ts
@@ -21,39 +21,8 @@ _global["setInterval"] = timer.setInterval;
 _global["clearTimeout"] = timer.clearTimer;
 _global["clearInterval"] = timer.clearTimer;
 
-const print = V8Worker2.print;
-
-_global["console"] = {
-  // tslint:disable-next-line:no-any
-  log(...args: any[]): void {
-    print(stringifyArgs(args));
-  },
-
-  // tslint:disable-next-line:no-any
-  error(...args: any[]): void {
-    print(`ERROR: ${stringifyArgs(args)}`);
-  },
-
-  // tslint:disable-next-line:no-any
-  assert(condition: boolean, ...args: any[]): void {
-    if (!condition) {
-      throw new Error(`Assertion failed: ${stringifyArgs(args)}`);
-    }
-  }
-};
-
-// tslint:disable-next-line:no-any
-function stringifyArgs(args: any[]): string {
-  const out: string[] = [];
-  for (const a of args) {
-    if (typeof a === "string") {
-      out.push(a);
-    } else {
-      out.push(JSON.stringify(a));
-    }
-  }
-  return out.join(" ");
-}
+import { Console } from "./console";
+_global["console"] = new Console();
 
 import { fetch } from "./fetch";
 _global["fetch"] = fetch;
diff --git a/tests.ts b/tests.ts
index 406ac76e86..f1412e1527 100644
--- a/tests.ts
+++ b/tests.ts
@@ -55,3 +55,74 @@ test(async function tests_writeFileSync() {
   const actual = dec.decode(dataRead);
   assertEqual("Hello", actual);
 });
+
+test(function tests_console_assert() {
+  console.assert(true);
+
+  let hasThrown = false;
+  try {
+    console.assert(false);
+  } catch {
+    hasThrown = true;
+  }
+  assertEqual(hasThrown, true);
+});
+
+test(function tests_console_stringify_circular() {
+  class Base {
+    a = 1;
+    m1() {}
+  }
+
+  class Extended extends Base {
+    b = 2;
+    m2() {}
+  }
+
+  // tslint:disable-next-line:no-any
+  const nestedObj: any = {
+    num: 1,
+    bool: true,
+    str: "a",
+    method() {},
+    un: undefined,
+    nu: null,
+    arrowFunc: () => {},
+    extendedClass: new Extended(),
+    nFunc: new Function(),
+    extendedCstr: Extended,
+  };
+
+  const circularObj = {
+    num: 2,
+    bool: false,
+    str: "b",
+    method() {},
+    un: undefined,
+    nu: null,
+    nested: nestedObj,
+    emptyObj: {},
+    arr: [1, "s", false, null, nestedObj],
+    baseClass: new Base(),
+  };
+
+  nestedObj.o = circularObj;
+
+  try {
+    console.log(1);
+    console.log("s");
+    console.log(false);
+    console.log(Symbol(1));
+    console.log(null);
+    console.log(undefined);
+    console.log(new Extended());
+    console.log(function f() {});
+    console.log(nestedObj);
+    console.log(JSON);
+    console.log(console);
+  } catch {
+    throw new Error(
+      "Expected no crash on circular object"
+    );
+  }
+});