diff --git a/src/slic3r/GUI/DeviceManager.cpp b/src/slic3r/GUI/DeviceManager.cpp
index b654834c6e4..fcafd0d3032 100644
--- a/src/slic3r/GUI/DeviceManager.cpp
+++ b/src/slic3r/GUI/DeviceManager.cpp
@@ -1258,11 +1258,11 @@ bool MachineObject::is_axis_at_home(std::string axis)
         return true;
 
     if (axis == "X") {
-        return home_flag & 1 == 1;
+        return (home_flag & 1) == 1;
     } else if (axis == "Y") {
-        return home_flag >> 1 & 1 == 1;
+        return (home_flag >> 1 & 1) == 1;
     } else if (axis == "Z") {
-        return home_flag >> 2 & 1 == 1;
+        return (home_flag >> 2 & 1) == 1;
     } else {
         return true;
     }
diff --git a/src/slic3r/GUI/Monitor.cpp b/src/slic3r/GUI/Monitor.cpp
index 6b9804e7374..8985e0d3a43 100644
--- a/src/slic3r/GUI/Monitor.cpp
+++ b/src/slic3r/GUI/Monitor.cpp
@@ -444,14 +444,14 @@ void MonitorPanel::show_status(int status)
 {
     if (!m_initialized) return;
     if (last_status == status)return;
-    if (last_status & (int)MonitorStatus::MONITOR_CONNECTING != 0) {
+    if ((last_status & (int)MonitorStatus::MONITOR_CONNECTING) != 0) {
         NetworkAgent* agent = wxGetApp().getAgent();
         json j;
         j["dev_id"] = obj ? obj->dev_id : "obj_nullptr";
-        if (status & (int)MonitorStatus::MONITOR_DISCONNECTED != 0) {
+        if ((status & (int)MonitorStatus::MONITOR_DISCONNECTED) != 0) {
             j["result"] = "failed";
         }
-        else if (status & (int)MonitorStatus::MONITOR_NORMAL != 0) {
+        else if ((status & (int)MonitorStatus::MONITOR_NORMAL) != 0) {
             j["result"] = "success";
         }
     }
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 61fbb23e16a..f5d017eb00b 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -6264,7 +6264,7 @@ void Plater::priv::on_slicing_update(SlicingStatusEvent &evt)
         for (auto const& warning : state.warnings) {
             if (warning.current) {
                 NotificationManager::NotificationLevel notif_level = NotificationManager::NotificationLevel::WarningNotificationLevel;
-                if (evt.status.message_type == PrintStateBase::SlicingNotificationType::SlicingReplaceInitEmptyLayers | PrintStateBase::SlicingNotificationType::SlicingEmptyGcodeLayers) {
+                if (evt.status.message_type == PrintStateBase::SlicingNotificationType::SlicingReplaceInitEmptyLayers || evt.status.message_type == PrintStateBase::SlicingNotificationType::SlicingEmptyGcodeLayers) {
                     notif_level = NotificationManager::NotificationLevel::SeriousWarningNotificationLevel;
                 }
                 notification_manager->push_slicing_warning_notification(warning.message, false, model_object, object_id, warning_step, warning.message_id, notif_level);
diff --git a/src/slic3r/GUI/Widgets/StateHandler.cpp b/src/slic3r/GUI/Widgets/StateHandler.cpp
index f66585fa343..eb3d3be71e0 100644
--- a/src/slic3r/GUI/Widgets/StateHandler.cpp
+++ b/src/slic3r/GUI/Widgets/StateHandler.cpp
@@ -71,7 +71,7 @@ void StateHandler::update_binds()
 
 void StateHandler::set_state(int state, int mask)
 {
-    if (states_ & mask == state & mask) return;
+    if ((states_ & mask) == (state & mask)) return;
     int old = states_;
     states_ = states_ & ~mask | state & mask;
     if (old != states_ && (old | states2_) != (states_ | states2_)) {