diff --git a/python/lammps.py b/python/lammps.py
index 62ed272d4b336c0e95a11777ba858c93478457f4..fdb898488a4d23faab66301b65c40eae9abc4017 100644
--- a/python/lammps.py
+++ b/python/lammps.py
@@ -110,7 +110,7 @@ class lammps(object):
       # allow for int (like MPICH) or void* (like OpenMPI)
 
       if comm:
-	if not lammps.has_mpi4py:
+        if not lammps.has_mpi4py:
           raise Exception('Python mpi4py version is not 2 or 3')
         if lammps.MPI._sizeof(lammps.MPI.Comm) == sizeof(c_int):
           MPI_Comm = c_int