diff --git a/libraries/networking/src/DomainHandler.cpp b/libraries/networking/src/DomainHandler.cpp
index 3213e7319a..c4b979e0b8 100644
--- a/libraries/networking/src/DomainHandler.cpp
+++ b/libraries/networking/src/DomainHandler.cpp
@@ -408,7 +408,7 @@ void DomainHandler::processDomainServerConnectionDeniedPacket(QSharedPointer<Rec
     qCWarning(networking) << "The domain-server denied a connection request: " << reasonMessage;
 
     if (!_domainConnectionRefusals.contains(reasonMessage)) {
-        _domainConnectionRefusals.append(reasonMessage);
+        _domainConnectionRefusals.insert(reasonMessage);
         emit domainConnectionRefused(reasonMessage, (int)reasonCode);
     }
 
diff --git a/libraries/networking/src/DomainHandler.h b/libraries/networking/src/DomainHandler.h
index be8ccbe50f..0c041da47d 100644
--- a/libraries/networking/src/DomainHandler.h
+++ b/libraries/networking/src/DomainHandler.h
@@ -144,7 +144,7 @@ private:
     QString _pendingPath;
     QTimer _settingsTimer;
 
-    QStringList _domainConnectionRefusals;
+    QSet<QString> _domainConnectionRefusals;
     bool _hasSignalledProtocolMismatch { false };
     bool _hasCheckedForAccessToken { false };
     int _connectionDenialsSinceKeypairRegen { 0 };