diff --git a/package-lock.json b/package-lock.json
index fb801cb..f1fbab7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -28,8 +28,8 @@
         "ts-mocha": "^10.0.0",
         "ts-node": "^10.9.2",
         "tsx": "^4.7.0",
-        "typescript": "^5.0.4",
-        "web-streams-polyfill": "^3.3.2"
+        "typescript": "^5.5.2",
+        "web-streams-polyfill": "^4.0.0"
       },
       "engines": {
         "node": ">= 18.0.0"
@@ -6048,9 +6048,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.3.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.3.3.tgz",
-      "integrity": "sha512-pXWcraxM0uxAS+tN0AG/BF2TyqmHO014Z070UsJ+pFvYuRSq8KH8DmWpnbXe0pEPDHXZV3FcAbJkijJ5oNEnWw==",
+      "version": "5.5.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.2.tgz",
+      "integrity": "sha512-NcRtPEOsPFFWjobJEtfihkLCZCXZt/os3zf8nTxjVH3RvTSxjrCamJpbExGvYOF+tFHc3pA65qpdwPbzjohhew==",
       "dev": true,
       "bin": {
         "tsc": "bin/tsc",
@@ -6224,9 +6224,9 @@
       }
     },
     "node_modules/web-streams-polyfill": {
-      "version": "3.3.2",
-      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-3.3.2.tgz",
-      "integrity": "sha512-3pRGuxRF5gpuZc0W+EpwQRmCD7gRqcDOMt688KmdlDAgAyaB1XlN0zq2njfDNm44XVdIouE7pZ6GzbdyH47uIQ==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-4.0.0.tgz",
+      "integrity": "sha512-0zJXHRAYEjM2tUfZ2DiSOHAa2aw1tisnnhU3ufD57R8iefL+DcdJyRBRyJpG+NUimDgbTI/lH+gAE1PAvV3Cgw==",
       "dev": true,
       "engines": {
         "node": ">= 8"
@@ -10889,9 +10889,9 @@
       }
     },
     "typescript": {
-      "version": "5.3.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.3.3.tgz",
-      "integrity": "sha512-pXWcraxM0uxAS+tN0AG/BF2TyqmHO014Z070UsJ+pFvYuRSq8KH8DmWpnbXe0pEPDHXZV3FcAbJkijJ5oNEnWw==",
+      "version": "5.5.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.2.tgz",
+      "integrity": "sha512-NcRtPEOsPFFWjobJEtfihkLCZCXZt/os3zf8nTxjVH3RvTSxjrCamJpbExGvYOF+tFHc3pA65qpdwPbzjohhew==",
       "dev": true
     },
     "ua-parser-js": {
@@ -11004,9 +11004,9 @@
       }
     },
     "web-streams-polyfill": {
-      "version": "3.3.2",
-      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-3.3.2.tgz",
-      "integrity": "sha512-3pRGuxRF5gpuZc0W+EpwQRmCD7gRqcDOMt688KmdlDAgAyaB1XlN0zq2njfDNm44XVdIouE7pZ6GzbdyH47uIQ==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-4.0.0.tgz",
+      "integrity": "sha512-0zJXHRAYEjM2tUfZ2DiSOHAa2aw1tisnnhU3ufD57R8iefL+DcdJyRBRyJpG+NUimDgbTI/lH+gAE1PAvV3Cgw==",
       "dev": true
     },
     "webpack": {
diff --git a/package.json b/package.json
index 2ebcf0c..123940f 100644
--- a/package.json
+++ b/package.json
@@ -46,8 +46,8 @@
     "ts-mocha": "^10.0.0",
     "ts-node": "^10.9.2",
     "tsx": "^4.7.0",
-    "typescript": "^5.0.4",
-    "web-streams-polyfill": "^3.3.2"
+    "typescript": "^5.5.2",
+    "web-streams-polyfill": "^4.0.0"
   },
   "peerDependencies": {
     "typescript": ">=4.2"
diff --git a/test/node.test.ts b/test/node.test.ts
index a624736..abb19ea 100644
--- a/test/node.test.ts
+++ b/test/node.test.ts
@@ -37,16 +37,16 @@ describe('Node integration tests', () => {
   it('polyfilled web stream cannot be converted into node native stream', async () => {
     const { ReadableStream: PolyfilledReadableStream } = await import ('web-streams-polyfill');
 
-    // this test is just to keep track that this behaviour is expected
+    // this test is just to keep track that this behaviour is expected: it does not cause a TS error, but a runtime one
     const input = 'chunk';
-    const stream = new PolyfilledReadableStream({
+    const stream: NodeWebReadableStream<string> = new PolyfilledReadableStream<string>({
       start(controller) {
         controller.enqueue(input);
         controller.close();
       }
     });
     const streamedData = toStream(stream);
-    // @ts-expect-error `fromWeb` does not accept the polyfilled stream
+    // `fromWeb` does not accept the polyfilled stream
     expect(() => NodeNativeReadableStream.fromWeb(streamedData)).to.throw(/must be an instance of ReadableStream/);
   });
 });
diff --git a/test/typescript.test.ts b/test/typescript.test.ts
index af19767..0103aa2 100644
--- a/test/typescript.test.ts
+++ b/test/typescript.test.ts
@@ -33,10 +33,10 @@ const newEmptyWebStream = <T extends Data>(): WebStream<T> => new WebReadableStr
   const expectedWebStreamButActualNodeStream: WebStream<string> = toStream(nodeWebStream);
   assert(expectedWebStreamButActualNodeStream instanceof NodeWebReadableStream);
   const newStringStream: Stream<string> = toStream('chunk');
-  assert(newStringStream instanceof WebReadableStream); // ReadableStream is polyfilled
+  assert(newStringStream instanceof NodeWebReadableStream);
   // @ts-expect-error detect type parameter mismatch
   const anotherStringStream: Stream<Uint8Array> = toStream('chunk');
-  assert(anotherStringStream instanceof WebReadableStream);  // ReadableStream is polyfilled
+  assert(anotherStringStream instanceof NodeWebReadableStream);
 
   assert(isArrayStream(new ArrayStream())) ; // ensure Array is actually extended in e.g. es5