diff --git a/garminexport/garminclient.py b/garminexport/garminclient.py
index b3a3351..aed53d8 100755
--- a/garminexport/garminclient.py
+++ b/garminexport/garminclient.py
@@ -376,14 +376,21 @@ class GarminClient(object):
                                      files=files, headers={"nk": "NT"})
 
         # check response and get activity ID
-        if response.status_code != 200:
+        try:
+            j = response.json()["detailedImportResult"]
+        except (json.JSONDecodeException, KeyError):
             raise Exception(u"failed to upload {} for activity: {}\n{}".format(
                 format, response.status_code, response.text))
 
-        j = response.json()
-        if len(j["detailedImportResult"]["failures"]) or len(j["detailedImportResult"]["successes"])!=1:
-            raise Exception(u"failed to upload {} for activity")
-        activity_id = j["detailedImportResult"]["successes"][0]["internalId"]
+        if len(j["failures"]) or len(j["successes"])<1:
+            raise Exception(u"failed to upload {} for activity: {}\n{}".format(
+                format, response.status_code, j["failures"]))
+
+        if len(j["successes"])>1:
+            raise Exception(u"uploading {} resulted in multiple activities ({})".format(
+                format, len(j["successes"])))
+
+        activity_id = j["successes"][0]["internalId"]
 
         # add optional fields
         fields = ( ('name',name,("display","value")),
diff --git a/upload_activity.py b/upload_activity.py
index e03440f..3198e44 100755
--- a/upload_activity.py
+++ b/upload_activity.py
@@ -29,7 +29,7 @@ if __name__ == "__main__":
     parser.add_argument(
         "username", metavar="<username>", type=str, help="Account user name.")
     parser.add_argument(
-        "activity", metavar="<file>", type=argparse.FileType("rb"),
+        "activity", nargs='+', metavar="<file>", type=argparse.FileType("rb"),
         help="Activity file (.gpx, .tcx, or .fit).")
 
     # optional args
@@ -47,6 +47,8 @@ if __name__ == "__main__":
               "Default: INFO."), default="INFO")
 
     args = parser.parse_args()
+    if len(args.activity)>1 and (args.description is not None or args.name is not None):
+        parser.error("When uploading multiple activities, --name or --description cannot be used.")
     if not args.log_level in LOG_LEVELS:
         raise ValueError("Illegal log-level argument: {}".format(
             args.log_level))
@@ -56,9 +58,14 @@ if __name__ == "__main__":
         if not args.password:
             args.password = getpass.getpass("Enter password: ")
         with GarminClient(args.username, args.password) as client:
-            log.info("uploading activity file {} ...".format(args.activity.name))
-            id = client.upload_activity(args.activity, name=args.name, description=args.description, private=args.private)
-            log.info("upload successful: https://connect.garmin.com/activity/{}".format(id))
+            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)
+                except Exception as e:
+                    log.error("upload failed: {}".format(e))
+                else:
+                    log.info("upload successful: https://connect.garmin.com/modern/activity/{}".format(id))
     except Exception as e:
         exc_type, exc_value, exc_traceback = sys.exc_info()
         log.error(u"failed with exception: %s", e)