diff --git a/workflows/MUSE/library.py b/workflows/MUSE/library.py
index 1e4e319eb669e12023d5d3374e75d0d08e9c1270..5f4f0544ee45227ec8e78e40b86ee3050b7538f5 100644
--- a/workflows/MUSE/library.py
+++ b/workflows/MUSE/library.py
@@ -100,7 +100,7 @@ def MUSE_string_to_file_finished(postdata, input_dict, output_dict):
     from socket import getfqdn
     import sys
 
-    if len(sys.argv > 1):
+    if len(sys.argv) > 1:
         DEVSERVER = sys.argv[1].startswith('runserver')
     else:
         DEVSERVER = False