diff --git a/garminexport/garminclient.py b/garminexport/garminclient.py
index aed53d8..019529a 100755
--- a/garminexport/garminclient.py
+++ b/garminexport/garminclient.py
@@ -393,21 +393,17 @@ class GarminClient(object):
         activity_id = j["successes"][0]["internalId"]
 
         # add optional fields
-        fields = ( ('name',name,("display","value")),
-                   ('description',description,("display","value")),
-                   ('type',activity_type,("activityType","key")),
-                   ('privacy','private' if private else None,("definition","key")) )
-        for endpoint, value, path in fields:
-            if value is not None:
-                response = self.session.post("https://connect.garmin.com/proxy/activity-service-1.2/json/{}/{}".format(endpoint, activity_id),
-                                             data={'value':value})
-                if response.status_code != 200:
-                    raise Exception(u"failed to set {} for activity {}: {}\n{}".format(
-                        endpoint, activity_id, response.status_code, response.text))
-
-                j = response.json()
-                p0, p1 = path
-                if p0 not in j or j[p0][p1] != value:
-                    raise Exception(u"failed to set {} for activity {}\n".format(endpoint, activity_id))
+        data = {}
+        if name is not None: data['activityName'] = name
+        if description is not None: data['description'] = name
+        if activity_type is not None: data['activityTypeDTO'] = {"typeKey": activity_type}
+        if private: data['privacy'] = {"typeKey": "private"}
+        if data:
+            data['activityId'] = activity_id
+            encoding_headers = {"Content-Type": "application/json; charset=UTF-8"} # see Tapiriik
+            response = self.session.put("https://connect.garmin.com/proxy/activity-service/activity/{}".format(activity_id), data=json.dumps(data), headers=encoding_headers)
+            if response.status_code != 204:
+                raise Exception(u"failed to set metadata for activity {}: {}\n{}".format(
+                    activity_id, response.status_code, response.text))
 
         return activity_id
diff --git a/upload_activity.py b/upload_activity.py
index 3198e44..37f2da0 100755
--- a/upload_activity.py
+++ b/upload_activity.py
@@ -41,6 +41,8 @@ if __name__ == "__main__":
         '-D', '--description', help="Activity description on Garmin Connect.")
     parser.add_argument(
         '-P', '--private', action='store_true', help="Make activity private on Garmin Connect.")
+    parser.add_argument(
+        '-T', '--type', help="Override activity type (running, cycling, walking, hiking, strength_training, etc.)")
     parser.add_argument(
         "--log-level", metavar="LEVEL", type=str,
         help=("Desired log output level (DEBUG, INFO, WARNING, ERROR). "
@@ -61,9 +63,9 @@ if __name__ == "__main__":
             for activity in args.activity:
                 log.info("uploading activity file {} ...".format(activity.name))
                 try:
-                    id = client.upload_activity(activity, name=args.name, description=args.description, private=args.private)
+                    id = client.upload_activity(activity, name=args.name, description=args.description, private=args.private, activity_type=args.type)
                 except Exception as e:
-                    log.error("upload failed: {}".format(e))
+                    log.error("upload failed: {!r}".format(e))
                 else:
                     log.info("upload successful: https://connect.garmin.com/modern/activity/{}".format(id))
     except Exception as e: