diff --git a/plugin/packages/wakatime/__about__.py b/plugin/packages/wakatime/__about__.py
index 04db754..538acdf 100644
--- a/plugin/packages/wakatime/__about__.py
+++ b/plugin/packages/wakatime/__about__.py
@@ -1,9 +1,9 @@
 __title__ = 'wakatime'
 __description__ = 'Common interface to the WakaTime api.'
 __url__ = 'https://github.com/wakatime/wakatime'
-__version_info__ = ('4', '1', '11')
+__version_info__ = ('4', '1', '13')
 __version__ = '.'.join(__version_info__)
 __author__ = 'Alan Hamlett'
 __author_email__ = 'alan@wakatime.com'
 __license__ = 'BSD'
-__copyright__ = 'Copyright 2014 Alan Hamlett'
+__copyright__ = 'Copyright 2016 Alan Hamlett'
diff --git a/plugin/packages/wakatime/constants.py b/plugin/packages/wakatime/constants.py
index 135039e..9db227f 100644
--- a/plugin/packages/wakatime/constants.py
+++ b/plugin/packages/wakatime/constants.py
@@ -14,3 +14,4 @@ SUCCESS = 0
 API_ERROR = 102
 CONFIG_FILE_PARSE_ERROR = 103
 AUTH_ERROR = 104
+UNKNOWN_ERROR = 105
diff --git a/plugin/packages/wakatime/main.py b/plugin/packages/wakatime/main.py
index 232f4ea..8e91bff 100644
--- a/plugin/packages/wakatime/main.py
+++ b/plugin/packages/wakatime/main.py
@@ -36,6 +36,7 @@ from .constants import (
     AUTH_ERROR,
     CONFIG_FILE_PARSE_ERROR,
     SUCCESS,
+    UNKNOWN_ERROR,
 )
 from .logger import setup_logging
 from .offlinequeue import Queue
@@ -345,7 +346,7 @@ def send_heartbeat(project=None, branch=None, hostname=None, stats={}, key=None,
         'Authorization': auth,
     }
     if hostname:
-        headers['X-Machine-Name'] = u(hostname)
+        headers['X-Machine-Name'] = u(hostname).encode('utf-8')
     proxies = {}
     if proxy:
         proxies['https'] = proxy
@@ -356,7 +357,7 @@ def send_heartbeat(project=None, branch=None, hostname=None, stats={}, key=None,
     except:
         tz = None
     if tz:
-        headers['TimeZone'] = u(tz.zone)
+        headers['TimeZone'] = u(tz.zone).encode('utf-8')
 
     session_cache = SessionCache()
     session = session_cache.get()
@@ -499,3 +500,4 @@ def execute(argv=None):
             return SUCCESS
     except:
         log.traceback()
+        return UNKNOWN_ERROR