diff --git a/cryptography/lib/src/browser/_javascript_bindings.dart b/cryptography/lib/src/browser/_javascript_bindings.dart
index 95caede..c244c48 100644
--- a/cryptography/lib/src/browser/_javascript_bindings.dart
+++ b/cryptography/lib/src/browser/_javascript_bindings.dart
@@ -24,10 +24,10 @@ import 'package:meta/meta.dart';
 /// Note that browsers support Web Cryptography only in secure contexts.
 @internal
 final bool isWebCryptoAvailable =
-    _subtle.isDefinedAndNotNull && _isSecureContext.toDart;
+    _subtle.isDefinedAndNotNull && (_isSecureContext?.toDart ?? false);
 
-@JS('window.isSecureContext')
-external JSBoolean get _isSecureContext;
+@JS('isSecureContext')
+external JSBoolean? get _isSecureContext;
 
 @JS('crypto.subtle')
 external JSAny get _subtle;
diff --git a/cryptography/lib/src/cryptography/secret_key.dart b/cryptography/lib/src/cryptography/secret_key.dart
index 88f5264..ab085e0 100644
--- a/cryptography/lib/src/cryptography/secret_key.dart
+++ b/cryptography/lib/src/cryptography/secret_key.dart
@@ -106,7 +106,7 @@ class SecretKeyData extends SecretKey {
   /// Generates _N_ random bytes.
   ///
   /// A description of the random number generator:
-  ///   * In browsers, `window.crypto.getRandomValues() is used directly.
+  ///   * In browsers, `crypto.getRandomValues()` is used directly.
   ///   * In other platforms, _dart:math_ [Random.secure()] is used.
   ///
   /// You can give a custom random number generator. This can be useful for
diff --git a/cryptography/lib/src/helpers/random_bytes_impl_browser.dart b/cryptography/lib/src/helpers/random_bytes_impl_browser.dart
index d1bde10..9bd850f 100644
--- a/cryptography/lib/src/helpers/random_bytes_impl_browser.dart
+++ b/cryptography/lib/src/helpers/random_bytes_impl_browser.dart
@@ -51,5 +51,5 @@ void fillBytesWithSecureRandom(Uint8List bytes, {Random? random}) {
   }
 }
 
-@JS('window.crypto.getRandomValues')
+@JS('crypto.getRandomValues')
 external void _webCryptoRandom(JSUint8Array buffer);