diff --git a/deps/undici/src/lib/client.js b/deps/undici/src/lib/client.js
index 1625b47eafe2aa..41fd4a753f8188 100644
--- a/deps/undici/src/lib/client.js
+++ b/deps/undici/src/lib/client.js
@@ -441,6 +441,7 @@ class Parser {
 
     this.keepAlive = ''
     this.contentLength = ''
+    this.connection = ''
     this.maxResponseSize = client[kMaxResponseSize]
   }
 
@@ -616,6 +617,8 @@ class Parser {
     const key = this.headers[len - 2]
     if (key.length === 10 && key.toString().toLowerCase() === 'keep-alive') {
       this.keepAlive += buf.toString()
+    } else if (key.length === 10 && key.toString().toLowerCase() === 'connection') {
+      this.connection += buf.toString()
     } else if (key.length === 14 && key.toString().toLowerCase() === 'content-length') {
       this.contentLength += buf.toString()
     }
@@ -709,7 +712,11 @@ class Parser {
     assert.strictEqual(this.timeoutType, TIMEOUT_HEADERS)
 
     this.statusCode = statusCode
-    this.shouldKeepAlive = shouldKeepAlive
+    this.shouldKeepAlive = (
+      shouldKeepAlive ||
+      // Override llhttp value which does not allow keepAlive for HEAD.
+      (request.method === 'HEAD' && !socket[kReset] && this.connection.toLowerCase() === 'keep-alive')
+    )
 
     if (this.statusCode >= 200) {
       const bodyTimeout = request.bodyTimeout != null
@@ -739,7 +746,7 @@ class Parser {
     this.headers = []
     this.headersSize = 0
 
-    if (shouldKeepAlive && client[kPipelining]) {
+    if (this.shouldKeepAlive && client[kPipelining]) {
       const keepAliveTimeout = this.keepAlive ? util.parseKeepAliveTimeout(this.keepAlive) : null
 
       if (keepAliveTimeout != null) {
@@ -769,7 +776,6 @@ class Parser {
     }
 
     if (request.method === 'HEAD') {
-      assert(socket[kReset])
       return 1
     }
 
@@ -843,6 +849,7 @@ class Parser {
     this.bytesRead = 0
     this.contentLength = ''
     this.keepAlive = ''
+    this.connection = ''
 
     assert(this.headers.length % 2 === 0)
     this.headers = []
@@ -1376,8 +1383,8 @@ function write (client, request) {
     socket[kReset] = true
   }
 
-  if (reset) {
-    socket[kReset] = true
+  if (reset != null) {
+    socket[kReset] = reset
   }
 
   if (client[kMaxRequests] && socket[kCounter]++ >= client[kMaxRequests]) {
diff --git a/deps/undici/src/lib/core/request.js b/deps/undici/src/lib/core/request.js
index e8a8f2a43dcc0e..bee1a872960666 100644
--- a/deps/undici/src/lib/core/request.js
+++ b/deps/undici/src/lib/core/request.js
@@ -144,7 +144,7 @@ class Request {
 
     this.blocking = blocking == null ? false : blocking
 
-    this.reset = reset == null ? false : reset
+    this.reset = reset == null ? null : reset
 
     this.host = null
 
diff --git a/deps/undici/src/lib/fetch/formdata.js b/deps/undici/src/lib/fetch/formdata.js
index a0c9e2f9373944..a957a80e02af7c 100644
--- a/deps/undici/src/lib/fetch/formdata.js
+++ b/deps/undici/src/lib/fetch/formdata.js
@@ -259,7 +259,7 @@ function makeEntry (name, value, filename) {
         lastModified: value.lastModified
       }
 
-      value = value instanceof File
+      value = (NativeFile && value instanceof NativeFile) || value instanceof UndiciFile
         ? new File([value], filename, options)
         : new FileLike(value, filename, options)
     }
diff --git a/deps/undici/src/lib/websocket/websocket.js b/deps/undici/src/lib/websocket/websocket.js
index 366b6aa3e275ac..79c9be439c1fb4 100644
--- a/deps/undici/src/lib/websocket/websocket.js
+++ b/deps/undici/src/lib/websocket/websocket.js
@@ -309,23 +309,14 @@ class WebSocket extends EventTarget {
       // not throw an exception must increase the bufferedAmount attribute
       // by the length of data’s buffer in bytes.
 
-      const ab = new ArrayBuffer(data.byteLength)
+      const ab = Buffer.from(data, data.byteOffset, data.byteLength)
 
-      if (Buffer.isBuffer(data)) {
-        // new Buffer signature is deprecated
-        Buffer.from(ab).set(data)
-      } else {
-        new data.constructor(ab).set(data)
-      }
-
-      const value = Buffer.from(ab)
-
-      const frame = new WebsocketFrameSend(value)
+      const frame = new WebsocketFrameSend(ab)
       const buffer = frame.createFrame(opcodes.BINARY)
 
-      this.#bufferedAmount += value.byteLength
+      this.#bufferedAmount += ab.byteLength
       socket.write(buffer, () => {
-        this.#bufferedAmount -= value.byteLength
+        this.#bufferedAmount -= ab.byteLength
       })
     } else if (isBlobLike(data)) {
       // If the WebSocket connection is established, and the WebSocket
diff --git a/deps/undici/src/package.json b/deps/undici/src/package.json
index 44e214624fbca7..02c3bf3857e8cd 100644
--- a/deps/undici/src/package.json
+++ b/deps/undici/src/package.json
@@ -1,6 +1,6 @@
 {
   "name": "undici",
-  "version": "5.15.0",
+  "version": "5.15.1",
   "description": "An HTTP/1.1 client, written from scratch for Node.js",
   "homepage": "https://undici.nodejs.org",
   "bugs": {
diff --git a/deps/undici/undici.js b/deps/undici/undici.js
index 05bcef21645300..a3c7eb571b555b 100644
--- a/deps/undici/undici.js
+++ b/deps/undici/undici.js
@@ -6088,7 +6088,7 @@ var require_formdata = __commonJS({
             type: value.type,
             lastModified: value.lastModified
           };
-          value = value instanceof File ? new File([value], filename, options) : new FileLike(value, filename, options);
+          value = NativeFile && value instanceof NativeFile || value instanceof UndiciFile ? new File([value], filename, options) : new FileLike(value, filename, options);
         }
       }
       return { name, value };
@@ -7505,7 +7505,7 @@ var require_request2 = __commonJS({
         this.origin = origin;
         this.idempotent = idempotent == null ? method === "HEAD" || method === "GET" : idempotent;
         this.blocking = blocking == null ? false : blocking;
-        this.reset = reset == null ? false : reset;
+        this.reset = reset == null ? null : reset;
         this.host = null;
         this.contentLength = null;
         this.contentType = null;
@@ -8869,6 +8869,7 @@ var require_client = __commonJS({
         this.bytesRead = 0;
         this.keepAlive = "";
         this.contentLength = "";
+        this.connection = "";
         this.maxResponseSize = client[kMaxResponseSize];
       }
       setTimeout(value, type) {
@@ -9004,6 +9005,8 @@ var require_client = __commonJS({
         const key = this.headers[len - 2];
         if (key.length === 10 && key.toString().toLowerCase() === "keep-alive") {
           this.keepAlive += buf.toString();
+        } else if (key.length === 10 && key.toString().toLowerCase() === "connection") {
+          this.connection += buf.toString();
         } else if (key.length === 14 && key.toString().toLowerCase() === "content-length") {
           this.contentLength += buf.toString();
         }
@@ -9067,7 +9070,7 @@ var require_client = __commonJS({
         }
         assert.strictEqual(this.timeoutType, TIMEOUT_HEADERS);
         this.statusCode = statusCode;
-        this.shouldKeepAlive = shouldKeepAlive;
+        this.shouldKeepAlive = shouldKeepAlive || request.method === "HEAD" && !socket[kReset] && this.connection.toLowerCase() === "keep-alive";
         if (this.statusCode >= 200) {
           const bodyTimeout = request.bodyTimeout != null ? request.bodyTimeout : client[kBodyTimeout];
           this.setTimeout(bodyTimeout, TIMEOUT_BODY);
@@ -9089,7 +9092,7 @@ var require_client = __commonJS({
         assert(this.headers.length % 2 === 0);
         this.headers = [];
         this.headersSize = 0;
-        if (shouldKeepAlive && client[kPipelining]) {
+        if (this.shouldKeepAlive && client[kPipelining]) {
           const keepAliveTimeout = this.keepAlive ? util.parseKeepAliveTimeout(this.keepAlive) : null;
           if (keepAliveTimeout != null) {
             const timeout = Math.min(keepAliveTimeout - client[kKeepAliveTimeoutThreshold], client[kKeepAliveMaxTimeout]);
@@ -9112,7 +9115,6 @@ var require_client = __commonJS({
           return -1;
         }
         if (request.method === "HEAD") {
-          assert(socket[kReset]);
           return 1;
         }
         if (statusCode < 200) {
@@ -9168,6 +9170,7 @@ var require_client = __commonJS({
         this.bytesRead = 0;
         this.contentLength = "";
         this.keepAlive = "";
+        this.connection = "";
         assert(this.headers.length % 2 === 0);
         this.headers = [];
         this.headersSize = 0;
@@ -9534,8 +9537,8 @@ var require_client = __commonJS({
       if (upgrade || method === "CONNECT") {
         socket[kReset] = true;
       }
-      if (reset) {
-        socket[kReset] = true;
+      if (reset != null) {
+        socket[kReset] = reset;
       }
       if (client[kMaxRequests] && socket[kCounter]++ >= client[kMaxRequests]) {
         socket[kReset] = true;
@@ -14518,18 +14521,12 @@ var require_websocket = __commonJS({
             this.#bufferedAmount -= value.byteLength;
           });
         } else if (ArrayBuffer.isView(data)) {
-          const ab = new ArrayBuffer(data.byteLength);
-          if (Buffer.isBuffer(data)) {
-            Buffer.from(ab).set(data);
-          } else {
-            new data.constructor(ab).set(data);
-          }
-          const value = Buffer.from(ab);
-          const frame = new WebsocketFrameSend(value);
+          const ab = Buffer.from(data, data.byteOffset, data.byteLength);
+          const frame = new WebsocketFrameSend(ab);
           const buffer = frame.createFrame(opcodes.BINARY);
-          this.#bufferedAmount += value.byteLength;
+          this.#bufferedAmount += ab.byteLength;
           socket.write(buffer, () => {
-            this.#bufferedAmount -= value.byteLength;
+            this.#bufferedAmount -= ab.byteLength;
           });
         } else if (isBlobLike(data)) {
           const frame = new WebsocketFrameSend();
diff --git a/src/undici_version.h b/src/undici_version.h
index 40875d828fbd5a..184417ee3bff1d 100644
--- a/src/undici_version.h
+++ b/src/undici_version.h
@@ -2,5 +2,5 @@
 // Refer to tools/update-undici.sh
 #ifndef SRC_UNDICI_VERSION_H_
 #define SRC_UNDICI_VERSION_H_
-#define UNDICI_VERSION "5.15.0"
+#define UNDICI_VERSION "5.15.1"
 #endif  // SRC_UNDICI_VERSION_H_