diff --git a/octoprint_filamentmanager/__init__.py b/octoprint_filamentmanager/__init__.py
index 3988788..dc26514 100644
--- a/octoprint_filamentmanager/__init__.py
+++ b/octoprint_filamentmanager/__init__.py
@@ -257,7 +257,7 @@ def calculate_weight(length, profile):
             volume = (length * PI * radius * radius) / 1000  # cm³
             return volume * profile["density"]  # g
 
-        for tool in xrange(0, numTools):
+        for tool in range(0, numTools):
             self._logger.info("Filament used: {length} mm (tool{id})"
                               .format(length=str(extrusion[tool]), id=str(tool)))
 
@@ -357,7 +357,7 @@ def get_update_information(self):
 
 
 __plugin_name__ = "Filament Manager"
-
+__plugin_pythoncompat__ = ">=2.7,<4"
 __required_octoprint_version__ = ">=1.3.6"
 
 
diff --git a/octoprint_filamentmanager/api/util.py b/octoprint_filamentmanager/api/util.py
index 76d03ff..df6d95b 100644
--- a/octoprint_filamentmanager/api/util.py
+++ b/octoprint_filamentmanager/api/util.py
@@ -17,4 +17,4 @@ def add_revalidation_header_with_no_max_age(response, lm, etag):
 
 
 def entity_tag(lm):
-    return (hashlib.sha1(str(lm))).hexdigest()
+    return (hashlib.sha1(str(lm).encode(encoding='UTF-8')).hexdigest())