diff --git a/lib/render_job.py b/lib/render_job.py
index 98affe0..4ba22eb 100644
--- a/lib/render_job.py
+++ b/lib/render_job.py
@@ -3,6 +3,7 @@ import hashlib
 import json
 import logging
 import os
+import threading
 import uuid
 from datetime import datetime
 
@@ -13,6 +14,11 @@ logger = logging.getLogger()
 
 class RenderJob:
 
+    # Get file hash on bg thread
+    def __get_file_hash(self):
+        if os.path.exists(self.worker.input_path):
+            self.file_hash = hashlib.md5(open(self.worker.input_path, 'rb').read()).hexdigest()
+
     def __init__(self, renderer, input_path, output_path, args, priority=2, owner=None, client=None, notify=None,
                  custom_id=None, name=None):
         self.id = custom_id or self.generate_id()
@@ -28,6 +34,9 @@ class RenderJob:
         self.worker = RenderWorkerFactory.create_worker(renderer, input_path, output_path, args)
         self.worker.log_path = os.path.join(os.path.dirname(input_path), self.name + '.log')
 
+        self.file_hash = None
+        threading.Thread(target=self.__get_file_hash).start()  # get file hash on bg thread
+
     def render_status(self):
         if self.scheduled_start and self.worker.status == RenderStatus.NOT_STARTED:
             return RenderStatus.SCHEDULED
@@ -46,7 +55,7 @@ class RenderJob:
             job_dict = self.__dict__.copy()
             job_dict['status'] = self.render_status().value
             job_dict['time_elapsed'] = self.time_elapsed() if type(self.time_elapsed) != str else self.time_elapsed
-            job_dict['file_hash'] = self.file_hash if self.file_hash and isinstance(self.file_hash, str) else self.file_hash()
+            job_dict['file_hash'] = self.file_hash
             job_dict['percent_complete'] = self.percent_complete()
             job_dict['file_list'] = self.file_list()
             job_dict['worker'] = self.worker.__dict__.copy()