diff --git a/src/dymoprint/dymo_print_engines.py b/src/dymoprint/dymo_print_engines.py
index 6243534..e6b9253 100644
--- a/src/dymoprint/dymo_print_engines.py
+++ b/src/dymoprint/dymo_print_engines.py
@@ -287,6 +287,9 @@ def print_label(
     equal to 1 are burned.
     """
 
+    if detected_device == None:
+        detected_device = detect_device()
+
     # Convert the image to the proper matrix for the dymo labeler object so that
     # rows span the width of the label, and the first row corresponds to the left
     # edge of the label.
diff --git a/src/dymoprint/gui.py b/src/dymoprint/gui.py
index 5790b34..d288503 100644
--- a/src/dymoprint/gui.py
+++ b/src/dymoprint/gui.py
@@ -161,7 +161,7 @@ def print_label(self):
         try:
             if self.label_bitmap is None:
                 raise RuntimeError("No label to print! Call update_label_render first.")
-            print_label(
+            print_label(None,
                 self.label_bitmap, self.margin.value(), self.tape_size.currentData()
             )
         except (RuntimeError, USBError) as err: