diff --git a/packtivity/handlers/publisher_handlers.py b/packtivity/handlers/publisher_handlers.py
index 9d3a47b..db61eee 100644
--- a/packtivity/handlers/publisher_handlers.py
+++ b/packtivity/handlers/publisher_handlers.py
@@ -6,6 +6,8 @@
 import logging
 import jq
 import os
+from six import string_types
+
 
 import packtivity.utils as utils
 
@@ -26,7 +28,7 @@ def interpolated_pub_handler(publisher,parameters,state):
     forinterp.update(workdir = state.readwrite[0])
     result = copy.deepcopy(publisher['publish'])
     for path,value in utils.leaf_iterator(publisher['publish']):
-        if not type(value) in [str, unicode]: continue
+        if not isinstance(value, string_types): continue
         resultval = value.format(**forinterp)
         globexpr = resultval
         if publisher['relative_paths'] and os.path.commonprefix([state.readwrite[0],globexpr]) == '':
@@ -55,7 +57,7 @@ def fromparjq_pub(publisher,parameters,state):
     result = jq.jq(publisher['script']).transform(inputjson)
     assert type(result)==dict
     for path,value in utils.leaf_iterator(result):
-        if not type(value) in [str, unicode]: continue
+        if not isinstance(value, string_types): continue
         if not state: break
         if state.readwrite:
             globdir = state.readwrite[0]