diff --git a/openmc/executor.py b/openmc/executor.py
index 74c56a9762..6dfb3566c6 100644
--- a/openmc/executor.py
+++ b/openmc/executor.py
@@ -35,7 +35,7 @@ class Executor(object):
             print(line, end='')
 
             # If OpenMC is finished, break loop
-            if line == '' and p.poll() != None:
+            if not line and p.poll() != None:
                 break
 
         # Return the returncode (integer, zero if no problems encountered)