diff --git a/libnymea-mqtt/mqttpacket.cpp b/libnymea-mqtt/mqttpacket.cpp
index 674a486..1710b60 100644
--- a/libnymea-mqtt/mqttpacket.cpp
+++ b/libnymea-mqtt/mqttpacket.cpp
@@ -111,7 +111,11 @@ void MqttPacket::setRetain(bool retain)
 
 void MqttPacket::setCleanSession(bool cleanSession)
 {
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagCleanSession, cleanSession);
+    if (cleanSession) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagCleanSession;
+    } else {
+        d_ptr->connectFlags &= ~Mqtt::ConnectFlagCleanSession;
+    }
 }
 
 bool MqttPacket::cleanSession() const
@@ -157,7 +161,11 @@ QByteArray MqttPacket::willTopic() const
 void MqttPacket::setWillTopic(const QByteArray &willTopic)
 {
     d_ptr->willTopic = willTopic;
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagWill, !willTopic.isEmpty());
+    if (!willTopic.isEmpty()) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagWill;
+    } else {
+        d_ptr->connectFlags &= ~Mqtt::ConnectFlagWill;
+    }
 }
 
 QByteArray MqttPacket::willMessage() const
@@ -183,8 +191,13 @@ Mqtt::QoS MqttPacket::willQoS() const
 
 void MqttPacket::setWillQoS(Mqtt::QoS willQoS)
 {
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagWillQoS1, willQoS == Mqtt::QoS1);
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagWillQoS2, willQoS == Mqtt::QoS2);
+    d_ptr->connectFlags &= ~Mqtt::ConnectFlagWillQoS1;
+    d_ptr->connectFlags &= ~Mqtt::ConnectFlagWillQoS2;
+    if (willQoS == Mqtt::QoS1) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagWillQoS1;
+    } else if (willQoS == Mqtt::QoS2) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagWillQoS2;
+    }
 }
 
 bool MqttPacket::willRetain() const
@@ -194,7 +207,11 @@ bool MqttPacket::willRetain() const
 
 void MqttPacket::setWillRetain(bool willRetain)
 {
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagWillRetain, willRetain);
+    if (willRetain) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagWillRetain;
+    } else {
+        d_ptr->connectFlags &= ~Mqtt::ConnectFlagWillRetain;
+    }
 }
 
 QByteArray MqttPacket::username() const
@@ -205,7 +222,11 @@ QByteArray MqttPacket::username() const
 void MqttPacket::setUsername(const QByteArray &username)
 {
     d_ptr->username = username;
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagUsername, !username.isEmpty());
+    if (!username.isEmpty()) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagUsername;
+    } else {
+        d_ptr->connectFlags &= ~Mqtt::ConnectFlagUsername;
+    }
 }
 
 QByteArray MqttPacket::password() const
@@ -216,7 +237,11 @@ QByteArray MqttPacket::password() const
 void MqttPacket::setPassword(const QByteArray &password)
 {
     d_ptr->password = password;
-    d_ptr->connectFlags.setFlag(Mqtt::ConnectFlagPassword, !password.isEmpty());
+    if (!password.isEmpty()) {
+        d_ptr->connectFlags |= Mqtt::ConnectFlagPassword;
+    } else {
+        d_ptr->connectFlags &= ~Mqtt::ConnectFlagPassword;
+    }
 }
 
 quint16 MqttPacket::keepAlive() const
diff --git a/libnymea-mqtt/mqttserver.cpp b/libnymea-mqtt/mqttserver.cpp
index 4d1a52d..be9820c 100644
--- a/libnymea-mqtt/mqttserver.cpp
+++ b/libnymea-mqtt/mqttserver.cpp
@@ -501,10 +501,10 @@ bool MqttServerPrivate::validateTopicFilter(const QString &topicFilter)
     QStringList parts = topicFilter.split('/');
     for (int i = 0; i < parts.count(); i++) {
         const QString &part = parts.at(i);
-        if (part.contains('#') && (part != '#' || i != parts.count() - 1)) {
+        if (part.contains(QStringLiteral("#")) && (part != QStringLiteral("#") || i != parts.count() - 1)) {
             return false;
         }
-        if (part.contains('+') && part != '+') {
+        if (part.contains(QStringLiteral("+")) && part != QStringLiteral("+")) {
             return false;
         }
     }
@@ -526,10 +526,10 @@ bool MqttServerPrivate::matchTopic(const QString &topicFilter, const QString &to
     }
 
     for (int i = 0; i < filterParts.count(); i++) {
-        if (filterParts.at(i) == '+') {
+        if (filterParts.at(i) == QStringLiteral("+")) {
             continue;
         }
-        if (filterParts.at(i) == '#') {
+        if (filterParts.at(i) == QStringLiteral("#")) {
             continue;
         }
         if (topicParts.at(i) == filterParts.at(i)) {