diff --git a/Libraries/LibWeb/Streams/AbstractOperations.cpp b/Libraries/LibWeb/Streams/AbstractOperations.cpp
index 6de2c390564..f872f25e6db 100644
--- a/Libraries/LibWeb/Streams/AbstractOperations.cpp
+++ b/Libraries/LibWeb/Streams/AbstractOperations.cpp
@@ -2017,7 +2017,9 @@ GC::Ref<WebIDL::Promise> readable_stream_reader_generic_cancel(ReadableStreamGen
 // https://streams.spec.whatwg.org/#readable-stream-reader-generic-initialize
 void readable_stream_reader_generic_initialize(ReadableStreamReader reader, ReadableStream& stream)
 {
-    auto& realm = stream.realm();
+    // FIXME: Exactly when we should effectively be using the relevant realm of `this` is to be clarified by the spec.
+    //        For now, we do so as needed by WPT tests. See: https://github.com/whatwg/streams/issues/1213
+    auto& realm = HTML::relevant_realm(reader.visit([](auto& reader) -> JS::Object& { return reader; }));
 
     // 1. Set reader.[[stream]] to stream.
     reader.visit([&](auto& reader) { reader->set_stream(stream); });
@@ -3574,7 +3576,9 @@ bool is_writable_stream_locked(WritableStream const& stream)
 // https://streams.spec.whatwg.org/#set-up-writable-stream-default-writer
 WebIDL::ExceptionOr<void> set_up_writable_stream_default_writer(WritableStreamDefaultWriter& writer, WritableStream& stream)
 {
-    auto& realm = writer.realm();
+    // FIXME: Exactly when we should effectively be using the relevant realm of `this` is to be clarified by the spec.
+    //        For now, we do so as needed by WPT tests. See: https://github.com/whatwg/streams/issues/1213
+    auto& realm = HTML::relevant_realm(writer);
 
     // 1. If ! IsWritableStreamLocked(stream) is true, throw a TypeError exception.
     if (is_writable_stream_locked(stream))
diff --git a/Tests/LibWeb/Text/expected/wpt-import/streams/readable-streams/global.txt b/Tests/LibWeb/Text/expected/wpt-import/streams/readable-streams/global.txt
index ba9f729ecac..b5dde1c6d8c 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/streams/readable-streams/global.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/streams/readable-streams/global.txt
@@ -2,11 +2,10 @@ Harness status: OK
 
 Found 9 tests
 
-8 Pass
-1 Fail
+9 Pass
 Pass	Stream objects created in expected globals
 Pass	Cancel promise is created in same global as stream
-Fail	Closed Promise in correct global
+Pass	Closed Promise in correct global
 Pass	Reader objects in correct global
 Pass	Desired size can be grafted from one prototype to another
 Pass	Closing errored stream throws object in appropriate global