diff --git a/python/lammps/formats.py b/python/lammps/formats.py
index a311867253..d34998f01c 100644
--- a/python/lammps/formats.py
+++ b/python/lammps/formats.py
@@ -19,9 +19,9 @@
 
 import re, yaml
 try:
-  from yaml import CSafeLoader as Loader, CSafeDumper as Dumper
+  from yaml import CSafeLoader as Loader
 except ImportError:
-  from yaml import SafeLoader as Loader, SafeDumper as Dumper
+  from yaml import SafeLoader as Loader
 
 class LogFile:
   """Reads LAMMPS log files and extracts the thermo information