diff --git a/dom/midi/MIDIAccess.cpp b/dom/midi/MIDIAccess.cpp
index 2ddb9b46940e..fa8ae514c29b 100644
--- a/dom/midi/MIDIAccess.cpp
+++ b/dom/midi/MIDIAccess.cpp
@@ -216,6 +216,8 @@ void MIDIAccess::Notify(const MIDIPortList& aEvent) {
     MaybeCreateMIDIPort(port, rv);
     if (rv.Failed()) {
       if (!mAccessPromise) {
+        // We can't reject the promise so let's suppress the error instead
+        rv.SuppressException();
         return;
       }
       mAccessPromise->MaybeReject(std::move(rv));