diff --git a/dedrm_src/mobidedrm.py b/dedrm_src/mobidedrm.py
index 501aa2d..cc7baf2 100644
--- a/dedrm_src/mobidedrm.py
+++ b/dedrm_src/mobidedrm.py
@@ -524,7 +524,7 @@ def cli_main():
     else:
         infile = argv[1]
         outfile = argv[2]
-        if len(argv) is 4:
+        if len(argv) == 4:
             pidlist = argv[3].split(',')
         else:
             pidlist = []