diff --git a/src/index.js b/src/index.js
index cbe5826..318da00 100644
--- a/src/index.js
+++ b/src/index.js
@@ -30,18 +30,40 @@ const isDuplexNodeStream = obj =>
   typeof obj.on === 'function' &&
   typeof obj.write === 'function';
 
+const isNodeStream = obj => {
+  return (
+    obj &&
+    (obj._readableState ||
+      obj._writableState ||
+      (typeof obj.write === 'function' && typeof obj.on === 'function') ||
+      (typeof obj.pipe === 'function' && typeof obj.on === 'function'))
+  );
+};
+
 const isReadableWebStream = obj =>
-  obj && globalThis.ReadableStream && obj instanceof globalThis.ReadableStream;
+  !!(
+    obj &&
+    !isNodeStream(obj) &&
+    typeof obj.pipeThrough === 'function' &&
+    typeof obj.getReader === 'function' &&
+    typeof obj.cancel === 'function'
+  );
 
 const isWritableWebStream = obj =>
-  obj && globalThis.WritableStream && obj instanceof globalThis.WritableStream;
+  !!(
+    obj &&
+    !isNodeStream(obj) &&
+    typeof obj.getWriter === 'function' &&
+    typeof obj.abort === 'function'
+  );
 
 const isDuplexWebStream = obj =>
-  obj &&
-  globalThis.ReadableStream &&
-  obj.readable instanceof globalThis.ReadableStream &&
-  globalThis.WritableStream &&
-  obj.writable instanceof globalThis.WritableStream;
+  !!(
+    obj &&
+    !isNodeStream(obj) &&
+    typeof obj.readable === 'object' &&
+    typeof obj.writable === 'object'
+  );
 
 const groupFunctions = (output, fn, index, fns) => {
   if (
@@ -239,7 +261,7 @@ module.exports.normalizeMany = defs.normalizeMany;
 module.exports.combineMany = defs.combineMany;
 module.exports.combineManyMut = defs.combineManyMut;
 
-module.exports.chain = chain;          // for compatibility with 2.x
+module.exports.chain = chain; // for compatibility with 2.x
 module.exports.chainUnchecked = chain; // for TypeScript to bypass type checks
 module.exports.gen = gen;
 module.exports.asStream = asStream;