diff --git a/README.md b/README.md
index 9517f8b..160ff57 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ Before :unamused: | After :tada:
 `42500` | `'42.5 kg'`
 `1250000` | `'1.25 MB'`
 `2700000000` | `'2.7 bil'`
+`1500000000000000000000000000000` | `'1.5 Q'`
 
 
 ## Install
@@ -67,4 +68,5 @@ Name | Type | Default | Description
 `locales` | `string \| Array<string>` | browser language | Formats the number in different languages
 `lowercase` | `boolean` | `false` | Use lowercase abbreviations
 `space` | `boolean` | `false` | Add a space between number and abbreviation
+`unsafeInteger` | `boolean` | `false` | Use unsafe numbers 
 `units` | `Array<string>` | `['', 'K', 'M', 'B', 'T', 'P', 'E']` | Unit abbreviations
diff --git a/bin/millify b/bin/millify
index bf0ffc0..516e3a0 100755
--- a/bin/millify
+++ b/bin/millify
@@ -35,6 +35,12 @@ require("yargs").command(
         type: "boolean",
         default: false,
       })
+      .option("unsafeInteger", {
+        describe: "Use unsafe integer",
+        alias: "U",
+        type: "boolean",
+        default: false,
+      })
       .option("units", {
         describe: "Unit abbreviatons",
         alias: "u",
diff --git a/lib/millify.ts b/lib/millify.ts
index 203e2bf..54151d2 100644
--- a/lib/millify.ts
+++ b/lib/millify.ts
@@ -48,7 +48,7 @@ function millify(value: number, options?: Partial<MillifyOptions>): string {
   // Originally this threw an error, but was changed to return a graceful fallback.
   let val: number;
   try {
-    val = parseValue(value);
+    val = parseValue(value, opts);
   } catch (e) {
     if (e instanceof Error) {
       console.warn(`WARN: ${e.message} (millify)`);
diff --git a/lib/options.ts b/lib/options.ts
index a71dbb5..62d0088 100644
--- a/lib/options.ts
+++ b/lib/options.ts
@@ -23,6 +23,10 @@ export interface MillifyOptions {
    * A list of units to use.
    */
   units: string[];
+  /**
+   * Use unsafe integer
+   * */
+  unsafeInteger: boolean;
 }
 
 /**
@@ -32,6 +36,7 @@ export const defaultOptions: MillifyOptions = {
   lowercase: false,
   precision: 1,
   space: false,
+  unsafeInteger: false,
   units: [
     "",
     "K", // Thousand
@@ -40,5 +45,9 @@ export const defaultOptions: MillifyOptions = {
     "T", // Trillion
     "P", // Quadrillion
     "E", // Quintillion
+    "Z", // Sextillion
+    "Y", // Septillion
+    "R", // Octillion
+    "Q", // Nonillion
   ],
 };
diff --git a/lib/utils.ts b/lib/utils.ts
index 9cbf138..e9be750 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -1,13 +1,27 @@
+import { MillifyOptions } from "./options";
+
 /**
  * parseValue ensures the value is a number and within accepted range.
  */
-export function parseValue(value: number): number {
+export function parseValue(
+  value: number,
+  options?: Partial<MillifyOptions>,
+): number {
   const val: number = parseFloat(value?.toString());
 
   if (isNaN(val)) {
     throw new Error(`Input value is not a number`);
   }
-  if (val > Number.MAX_SAFE_INTEGER || val < Number.MIN_SAFE_INTEGER) {
+  if (
+    options?.unsafeInteger &&
+    (val > Number.MAX_VALUE || val < Number.MIN_VALUE)
+  ) {
+    throw new RangeError("Input value is outside of unsafe integer range");
+  }
+  if (
+    !options?.unsafeInteger &&
+    (val > Number.MAX_SAFE_INTEGER || val < Number.MIN_SAFE_INTEGER)
+  ) {
     throw new RangeError("Input value is outside of safe integer range");
   }
   return val;
diff --git a/test.js b/test.js
index d2b4613..fd1a573 100644
--- a/test.js
+++ b/test.js
@@ -12,6 +12,35 @@ test("uses correct suffixes with default options", (t) => {
     [1000000, "1M"],
     [1000000000, "1B"],
     [1000000000000, "1T"],
+    [1000000000000000, "1P"],
+  ]);
+
+  for (const [value, expected] of tests.entries()) {
+    t.is(millify(value), expected);
+  }
+});
+
+test("uses correct suffixes with 'unsafeInteger' option", (t) => {
+  const tests = new Map([
+    [1000000000000000000, "1E"],
+    [1000000000000000000000, "1Z"],
+    [1000000000000000000000000, "1Y"],
+    [1000000000000000000000000000, "1R"],
+    [1700000000000000000000000000000, "1.7Q"],
+  ]);
+
+  for (const [value, expected] of tests.entries()) {
+    t.is(millify(value, { unsafeInteger: true }), expected);
+  }
+});
+
+test("uses correct suffixes without 'unsafeInteger' option", (t) => {
+  const tests = new Map([
+    ["1000000000000000000", "1000000000000000000"],
+    ["1000000000000000000000", "1000000000000000000000"],
+    ["1000000000000000000000000", "1000000000000000000000000"],
+    ["1000000000000000000000000000", "1000000000000000000000000000"],
+    ["1000000000000000000000000000000", "1000000000000000000000000000000"],
   ]);
 
   for (const [value, expected] of tests.entries()) {