diff --git a/python/lammps.py b/python/lammps.py
index c6a4b6168e..81016f6349 100644
--- a/python/lammps.py
+++ b/python/lammps.py
@@ -125,12 +125,15 @@ class lammps:
     return self.lib.lammps_version(self.lmp)
 
   def file(self,file):
+    file = file.encode()
     self.lib.lammps_file(self.lmp,file)
 
   def command(self,cmd):
+    cmd = cmd.encode()
     self.lib.lammps_command(self.lmp,cmd)
 
   def extract_global(self,name,type):
+    name = name.encode()
     if type == 0:
       self.lib.lammps_extract_global.restype = POINTER(c_int)
     elif type == 1:
@@ -140,6 +143,7 @@ class lammps:
     return ptr[0]
 
   def extract_atom(self,name,type):
+    name = name.encode()
     if type == 0:
       self.lib.lammps_extract_atom.restype = POINTER(c_int)
     elif type == 1:
@@ -153,6 +157,7 @@ class lammps:
     return ptr
 
   def extract_compute(self,id,style,type):
+    id = id.encode()
     if type == 0:
       if style > 0: return None
       self.lib.lammps_extract_compute.restype = POINTER(c_double)
@@ -172,6 +177,7 @@ class lammps:
   # double was allocated by library interface function
   
   def extract_fix(self,id,style,type,i=0,j=0):
+    id = ide.encode()
     if style == 0:
       self.lib.lammps_extract_fix.restype = POINTER(c_double)
       ptr = self.lib.lammps_extract_fix(self.lmp,id,style,type,i,j)
@@ -195,6 +201,8 @@ class lammps:
   # memory was allocated by library interface function
   
   def extract_variable(self,name,group,type):
+    name = name.encode()
+    group = group.encode()
     if type == 0:
       self.lib.lammps_extract_variable.restype = POINTER(c_double)
       ptr = self.lib.lammps_extract_variable(self.lmp,name,group)
@@ -218,6 +226,8 @@ class lammps:
   # returns 0 for success, -1 if failed
   
   def set_variable(self,name,value):
+    name = name.encode()
+    value = str(value).encode()
     return self.lib.lammps_set_variable(self.lmp,name,str(value))
 
   # return total number of atoms in system
@@ -228,6 +238,7 @@ class lammps:
   # return vector of atom properties gathered across procs, ordered by atom ID
 
   def gather_atoms(self,name,type,count):
+    name = name.encode()
     natoms = self.lib.lammps_get_natoms(self.lmp)
     if type == 0:
       data = ((count*natoms)*c_int)()
@@ -242,4 +253,7 @@ class lammps:
   # assume vector is of correct type and length, as created by gather_atoms()
 
   def scatter_atoms(self,name,type,count,data):
+    name = name.encode()
     self.lib.lammps_scatter_atoms(self.lmp,name,type,count,data)
+
+