diff --git a/app.py b/app.py
index c2c87ae..a96b6f3 100644
--- a/app.py
+++ b/app.py
@@ -14,6 +14,8 @@ import time
 
 app = Flask(__name__)
 
+printer_busy = False
+
 # Set up logging
 log_file = 'log.txt'
 
@@ -116,10 +118,13 @@ def save_images(images, pdf_path):
 
 # Worker thread that processes files from the queue
 def file_worker():
+    global printer_busy
     while True:
         file_path = file_queue.get()
         if file_path is None:  # Shutdown signal
             break
+        while printer_busy:
+            time.sleep(1)
         app.logger.info(f"Processing file: {file_path}")
         images = convert_pdf_to_images(file_path)
         if images:
@@ -130,11 +135,16 @@ def file_worker():
 
 # Printer worker
 def printer_worker():
+    global printer_busy
     while True:
         image, path = image_queue.get()
         if image is None:
+            if printer_busy:
+                time.sleep(10)
+                printer_busy = False
             break
         with lock:
+            printer_busy = True
             print_address_label(image, path)
         image_queue.task_done()