diff --git a/package.json b/package.json
index 845bdce..6100878 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "url-normalize",
-  "version": "1.1.1",
+  "version": "1.2.0",
   "author": "Vlad Pronsky <v.pronsky@gmail.com>",
   "repository": "vladkens/url-normalize",
   "description": "Normalize URLs to a standardized form by removing unnecessary characters, decoding encoded characters, removing default index pages, removing trailing slashes, and more.",
@@ -26,6 +26,7 @@
     "main": "dist/main.cjs",
     "exports": "dist/main.mjs"
   },
+  "types": "./dist/main.d.ts",
   "exports": {
     "types": "./dist/main.d.ts",
     "import": "./dist/main.mjs",
diff --git a/readme.md b/readme.md
index 2a9ef43..3574c02 100644
--- a/readme.md
+++ b/readme.md
@@ -13,7 +13,7 @@
   <!-- <a href="https://npmjs.org/package/url-normalize">
     <img src="https://badgen.net/npm/dm/url-normalize" alt="downloads" />
   </a> -->
-  <a href="https://npmjs.org/package/url-normalize">
+  <a href="https://github.com/vladkens/url-normalize/blob/main/LICENSE">
     <img src="https://badgen.net/npm/licence/url-normalize" alt="license" />
   </a>
 </div>
@@ -66,9 +66,25 @@ urlNormalize("https://example.com", { defaultProtocol: "http" })
 // -> "https://example.com"
 ```
 
+#### keepProtocol `(default: true)`
+
+```typescript
+urlNormalize("https://example.com")
+// -> "https://example.com"
+
+urlNormalize("https://example.com", { keepProtocol: false })
+// -> "example.com"
+
+urlNormalize("https://example.com/foo?bar=baz", { keepProtocol: false })
+// -> "example.com/foo?bar=baz"
+```
+
 #### keepWWW `(default: false)`
 
 ```typescript
+urlNormalize("www.example.com")
+// -> "https://example.com"
+
 urlNormalize("www.example.com", { keepWWW: true })
 // -> "https://www.example.com"
 ```
@@ -163,6 +179,16 @@ urlNormalize("tg://example.com", { allowCustomProtocol: true })
 // -> "tg://example.com"
 ```
 
+#### forceProtocol
+
+```typescript
+urlNormalize("https://example.com", { forceProtocol: "sftp" })
+// -> "sftp://example.com"
+
+urlNormalize("tg://example.com", { forceProtocol: "we" })
+// -> "we://example.com"
+```
+
 ### Advanced
 
 #### urlNormalizeOrFail
diff --git a/src/main.ts b/src/main.ts
index 54cc2df..c67fe32 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,10 +1,12 @@
 export type Options = {
   allowCustomProtocol?: boolean
   defaultProtocol?: string
+  forceProtocol?: string
   keepAuth?: boolean
   keepDirectoryIndex?: boolean
   keepHash?: boolean
   keepPort?: boolean // default port always removed
+  keepProtocol?: boolean
   keepQueryParams?: boolean
   keepTextFragment?: boolean
   keepWWW?: boolean
@@ -18,6 +20,7 @@ const DefaultOptions: Options = {
   keepDirectoryIndex: true,
   keepHash: true,
   keepPort: true,
+  keepProtocol: true,
   keepQueryParams: true,
   keepTextFragment: false,
   keepWWW: false,
@@ -46,7 +49,8 @@ export const urlNormalizeOrFail = (url: string, options?: Options): string => {
 
   if (
     !options.allowCustomProtocol &&
-    !["http:", "https:", `${options.defaultProtocol}:`].includes(obj.protocol)
+    !["http:", "https:", `${options.defaultProtocol}:`].includes(obj.protocol) &&
+    !options.forceProtocol // URL in nodejs not allow to change protocol, so do it on the end
   ) {
     throw new Error("Invalid protocol")
   }
@@ -105,12 +109,24 @@ export const urlNormalizeOrFail = (url: string, options?: Options): string => {
   let res = obj.toString()
   if (res.endsWith("/") && !res.endsWith("/#/")) res = res.slice(0, -1)
 
+  let protocol = obj.protocol
+  if (options.forceProtocol) {
+    const regex = new RegExp(`^${obj.protocol}//`, "i")
+    res = res.replace(regex, `${options.forceProtocol}://`)
+    protocol = `${options.forceProtocol}:`
+  }
+
+  if (!options.keepProtocol) {
+    const regex = new RegExp(`^${protocol}//`, "i")
+    res = res.replace(regex, "")
+  }
+
   return res
 }
 
-export const urlNormalize = (url: string, options?: Options): string | null => {
+export const urlNormalize = (url?: string | null, options?: Options): string | null => {
   try {
-    return urlNormalizeOrFail(url, options)
+    return urlNormalizeOrFail(url ?? "", options)
   } catch {
     return null
   }
@@ -122,9 +138,9 @@ export const extractDomainOrFail = (url: string): string => {
   return obj.hostname
 }
 
-export const extractDomain = (url: string): string | null => {
+export const extractDomain = (url?: string | null): string | null => {
   try {
-    return extractDomainOrFail(url)
+    return extractDomainOrFail(url ?? "")
   } catch {
     return null
   }
diff --git a/tests/main.test.ts b/tests/main.test.ts
index b000cae..b0fe2a8 100644
--- a/tests/main.test.ts
+++ b/tests/main.test.ts
@@ -143,6 +143,23 @@ test("should allow custom options", () => {
   t(`abc://www.example.com/foo/bar`, null, { allowCustomProtocol: false })
   t(`abc://www.example.com/foo/bar`, null, { allowCustomProtocol: false })
 
+  // keep protocol
+  t("https://example.com", "https://example.com", { keepProtocol: true })
+  t("https://example.com", "example.com", { keepProtocol: false })
+  t("https://example.com/abc", "example.com/abc", { keepProtocol: false })
+  t("https://example.com:80/abc", "example.com:80/abc", { keepProtocol: false })
+  t("https://example.com/foo?bar=baz", "example.com/foo?bar=baz", { keepProtocol: false })
+  t("abc://example.com:80/abc", "example.com:80/abc", { keepProtocol: false, allowCustomProtocol: true })
+  t("abc://example.com:80/abc", null, { keepProtocol: false, allowCustomProtocol: false })
+
+  // force protocol
+  t("https://example.com", "http://example.com", { forceProtocol: "http" })
+  t("https://example.com", "https://example.com", { forceProtocol: "https" })
+  t("https://example.com", "abc://example.com", { forceProtocol: "abc" })
+  t("https://example.com", "example.com", { forceProtocol: "abc", keepProtocol: false })
+  t("https://example.com", "sftp://example.com", { forceProtocol: "sftp" })
+  t("tg://example.com", "we://example.com", { forceProtocol: "we" })
+
   // keep www
   t("www.example.com", "https://www.example.com", { keepWWW: true })
   t("www.example.com", "https://example.com", { keepWWW: false })