diff --git a/dom/fetch/FetchStreamReader.cpp b/dom/fetch/FetchStreamReader.cpp
index 57fa4e3c4570..a439061a4f78 100644
--- a/dom/fetch/FetchStreamReader.cpp
+++ b/dom/fetch/FetchStreamReader.cpp
@@ -291,6 +291,11 @@ FetchStreamReader::OnOutputStreamReady(nsIAsyncOutputStream* aStream) {
 
   ReadableStreamDefaultReaderRead(aes.cx(), MOZ_KnownLive(mReader), readRequest,
                                   rv);
+
+  // We report the (potential) JS Exception via the AutoEntryScript above, as
+  // was done in the JS Streams implementation as well.
+  rv.WouldReportJSException();
+
   if (NS_WARN_IF(rv.Failed())) {
     // Let's close the stream.
     CloseAndRelease(aes.cx(), NS_ERROR_DOM_INVALID_STATE_ERR);