diff --git a/plugins/USBPrinting/USBPrinterManager.py b/plugins/USBPrinting/USBPrinterManager.py
index 88c696c2c9..5982196cb8 100644
--- a/plugins/USBPrinting/USBPrinterManager.py
+++ b/plugins/USBPrinting/USBPrinterManager.py
@@ -133,30 +133,34 @@ class USBPrinterManager(QObject, SignalEmitter, OutputDevicePlugin, Extension):
 
     def _getDefaultFirmwareName(self):
         machine_type = Application.getInstance().getMachineManager().getActiveMachineInstance().getMachineDefinition().getId()
-        firmware_name = ""
         baudrate = 250000
         if sys.platform.startswith("linux"):
                 baudrate = 115200
         if machine_type == "ultimaker_original":
             firmware_name = "MarlinUltimaker"
             firmware_name += "-%d" % (baudrate)
+            return firmware_name + ".hex"
         elif machine_type == "ultimaker_original_plus":
             firmware_name = "MarlinUltimaker-UMOP-%d" % (baudrate)
-        elif machine_type == "Witbox":
+            return firmware_name + ".hex"
+        elif machine_type == "bq_witbox":
             return "MarlinWitbox.hex"
-        elif machine_type == "ultimaker2go":
+        elif machine_type == "ultimaker2_go":
             return "MarlinUltimaker2go.hex"
-        elif machine_type == "ultimaker2extended":
+        elif machine_type == "ultimaker2_extended":
             return "MarlinUltimaker2extended.hex"
         elif machine_type == "ultimaker2":
             return "MarlinUltimaker2.hex"
+        elif machine_type == "ultimaker2plus":
+            return "MarlinUltimaker2plus.hex"
+        elif machine_type == "ultimaker2_extended_plus":
+            return "MarlinUltimaker2extended-plus.hex"
+        else:
+            Logger.log("e", "I don't know of any firmware for machine %s.", machine_type)
+            raise FileNotFoundError()
 
         ##TODO: Add check for multiple extruders
 
-        if firmware_name != "":
-            firmware_name += ".hex"
-        return firmware_name
-
     def _addRemovePorts(self, serial_ports):
         # First, find and add all new or changed keys
         for serial_port in list(serial_ports):
diff --git a/resources/machines/ultimaker2_extended_plus.json b/resources/machines/ultimaker2_extended_plus.json
index 5f74df23c7..403340cbe3 100644
--- a/resources/machines/ultimaker2_extended_plus.json
+++ b/resources/machines/ultimaker2_extended_plus.json
@@ -1,5 +1,5 @@
 {
-    "id": "ultimaker2_extended_plus_base",
+    "id": "ultimaker2_extended_plus",
     "version": 1, 
     "name": "Ultimaker 2 Extended+",
     "manufacturer": "Ultimaker",
diff --git a/resources/machines/ultimaker2plus.json b/resources/machines/ultimaker2plus.json
index b75e66122d..8c1c24663f 100644
--- a/resources/machines/ultimaker2plus.json
+++ b/resources/machines/ultimaker2plus.json
@@ -1,5 +1,5 @@
 {
-    "id": "ultimaker2plus_base",
+    "id": "ultimaker2plus",
     "version": 1, 
     "name": "Ultimaker 2+",
     "manufacturer": "Ultimaker",