diff --git a/octoprint_printhistory/__init__.py b/octoprint_printhistory/__init__.py
index f2eeb4c..5dd3a0d 100644
--- a/octoprint_printhistory/__init__.py
+++ b/octoprint_printhistory/__init__.py
@@ -8,6 +8,7 @@
 
 from flask import jsonify, request, make_response
 from octoprint.server.util.flask import with_revalidation_checking, check_etag
+__plugin_pythoncompat__ = ">=2.7,<4"
 
 import octoprint.plugin
 import sqlite3
diff --git a/octoprint_printhistory/parser.py b/octoprint_printhistory/parser.py
index 63d9c9a..51d4b4d 100644
--- a/octoprint_printhistory/parser.py
+++ b/octoprint_printhistory/parser.py
@@ -4,8 +4,15 @@
 import json
 import logging
 import unittest
-import StringIO
-import ConfigParser
+
+import sys
+if sys.version_info >= (3,0):
+    import configparser
+    from io import StringIO
+else:
+    import ConfigParser
+    import StringIO
+
 
 VERSION_REGEX = re.compile(r"(\d+)?\.(\d+)?\.?(\*|\d+)")
 BUFFER_SIZE = 8192