diff --git a/cura/MachineManagerModel.py b/cura/MachineManagerModel.py
index d9903744ee..92ce86804d 100644
--- a/cura/MachineManagerModel.py
+++ b/cura/MachineManagerModel.py
@@ -75,16 +75,16 @@ class MachineManagerModel(QObject):
 
     def _onOutputDevicesChanged(self):
         for printer_output_device in self._printer_output_devices:
-            printer_output_device.HotendIdChanged.disconnect(self._onHotendIdChanged)
-            printer_output_device.MaterialIdChanged.disconnect(self._onMaterialIdChanged)
+            printer_output_device.hotendIdChanged.disconnect(self._onHotendIdChanged)
+            printer_output_device.materialIdChanged.disconnect(self._onMaterialIdChanged)
 
         self._printer_output_devices.clear()
 
         for printer_output_device in Application.getInstance().getOutputDeviceManager().getOutputDevices():
             if isinstance(printer_output_device, PrinterOutputDevice):
                 self._printer_output_devices.append(printer_output_device)
-                printer_output_device.HotendIdChanged.connect(self._onHotendIdChanged)
-                printer_output_device.MaterialIdChanged.connect(self._onMaterialIdChanged)
+                printer_output_device.hotendIdChanged.connect(self._onHotendIdChanged)
+                printer_output_device.materialIdChanged.connect(self._onMaterialIdChanged)
 
         self.outputDevicesChanged.emit()
 
diff --git a/cura/PrinterOutputDevice.py b/cura/PrinterOutputDevice.py
index 6504de9cdd..212ed86ab3 100644
--- a/cura/PrinterOutputDevice.py
+++ b/cura/PrinterOutputDevice.py
@@ -60,10 +60,10 @@ class PrinterOutputDevice(QObject, OutputDevice):
     headPositionChanged = pyqtSignal()
 
     # Signal to be emitted when either of the material ids is changed
-    MaterialIdChanged = pyqtSignal(int, str, arguments = ["index", "id"])
+    materialIdChanged = pyqtSignal(int, str, arguments = ["index", "id"])
 
     # Signal to be emitted when either of the hotend ids is changed
-    HotendIdChanged = pyqtSignal(int, str, arguments = ["index", "id"])
+    hotendIdChanged = pyqtSignal(int, str, arguments = ["index", "id"])
 
     # Signal that is emitted every time connection state is changed.
     # it also sends it's own device_id (for convenience sake)
@@ -220,7 +220,7 @@ class PrinterOutputDevice(QObject, OutputDevice):
         self._hotend_temperatures[index] = temperature
         self.hotendTemperaturesChanged.emit()
 
-    @pyqtProperty("QVariantList", notify = MaterialIdChanged)
+    @pyqtProperty("QVariantList", notify = materialIdChanged)
     def materialIds(self):
         return self._material_ids
 
@@ -231,10 +231,10 @@ class PrinterOutputDevice(QObject, OutputDevice):
         if material_id and material_id != "" and material_id != self._material_ids[index]:
             Logger.log("d", "Setting material id of hotend %d to %s" % (index, material_id))
             self._material_ids[index] = material_id
-            self.MaterialIdChanged.emit(index, material_id)
+            self.materialIdChanged.emit(index, material_id)
 
 
-    @pyqtProperty("QVariantList", notify = HotendIdChanged)
+    @pyqtProperty("QVariantList", notify = hotendIdChanged)
     def hotendIds(self):
         return self._hotend_ids
 
@@ -245,7 +245,7 @@ class PrinterOutputDevice(QObject, OutputDevice):
         if hotend_id and hotend_id != "" and hotend_id != self._hotend_ids[index]:
             Logger.log("d", "Setting hotend id of hotend %d to %s" % (index, hotend_id))
             self._hotend_ids[index] = hotend_id
-            self.HotendIdChanged.emit(index, hotend_id)
+            self.hotendIdChanged.emit(index, hotend_id)
 
 
     ##  Attempt to establish connection