diff --git a/oxasl/basil.py b/oxasl/basil.py
index 6840436..d62a1c3 100644
--- a/oxasl/basil.py
+++ b/oxasl/basil.py
@@ -443,7 +443,8 @@ def run(self, prev_output, progress_log=sys.stdout, log=sys.stdout):
             self.options["continue-from-mvn"] = prev_output["finalMVN"]
         from .wrappers import fabber
         ret = fabber(self.options, output=LOAD, progress_log=progress_log, log={"stdout" : log})
-        log.write("\n")
+        if log is not None:
+            log.write("\n")
         return ret
 
 class PvcInitStep(Step):