--- a/taskcluster/taskgraph/parameters.py
+++ b/taskcluster/taskgraph/parameters.py
@@ -65,23 +65,25 @@ def load_parameters_file(options):
 
     url_prefix = "https://public-artifacts.taskcluster.net/"
     url_postfix = "/0/public/parameters.yml"
 
     filename = options['parameters']
 
     if not filename:
         return Parameters()
-    elif filename.startswith(url_prefix):
+
+    try:
+        # reading parameters from a local parameters.yml file
+        f = open(filename)
+    except IOError:
+        # fetching parameters.yml using task task-id or supplied url
+        if filename.startswith("parameters-from-task="):
+            task_id = filename.split("=")[1]
+            filename = url_prefix + task_id + url_postfix
         f = urllib.urlopen(filename)
-    elif filename.startswith("parameters-from-task="):
-        task_id = filename.split("=")[1]
-        filename = url_prefix + task_id + url_postfix
-        f = urllib.urlopen(filename)
-    else:
-        f = open(filename)
 
     if filename.endswith('.yml'):
         return Parameters(**yaml.safe_load(f))
     elif filename.endswith('.json'):
         return Parameters(**json.load(f))
     else:
         raise TypeError("Parameters file `{}` is not JSON or YAML".format(filename))