diff --git a/senpy/api.py b/senpy/api.py
index 5d9b8b9..5f20cb1 100644
--- a/senpy/api.py
+++ b/senpy/api.py
@@ -175,8 +175,8 @@ def parse_params(indict, *specs):
             parameters=outdict,
             errors=wrong_params)
         raise message
-    if 'algorithm' in outdict and not isinstance(outdict['algorithm'], list):
-        outdict['algorithm'] = list(outdict['algorithm'].split(','))
+    if 'algorithm' in outdict and not isinstance(outdict['algorithm'], tuple):
+        outdict['algorithm'] = tuple(outdict['algorithm'].split(','))
     return outdict
 
 
diff --git a/senpy/blueprints.py b/senpy/blueprints.py
index 33598d7..8fc696f 100644
--- a/senpy/blueprints.py
+++ b/senpy/blueprints.py
@@ -196,7 +196,7 @@ def api_root(plugin):
     if plugin:
         plugin = plugin.replace('+', '/')
         plugin = plugin.split('/')
-        req.parameters['algorithm'] = plugin
+        req.parameters['algorithm'] = tuple(plugin)
     return current_app.senpy.analyse(req)
 
 
diff --git a/tests/test_blueprints.py b/tests/test_blueprints.py
index ebe523d..51a11e2 100644
--- a/tests/test_blueprints.py
+++ b/tests/test_blueprints.py
@@ -74,6 +74,7 @@ class BlueprintsTest(TestCase):
         The results for a POST request should be the same as for a GET request.
         """
         resp = self.client.post("/api/", data={'i': 'My aloha mohame',
+                                               'algorithm': 'rand',
                                                'with_parameters': True})
         self.assertCode(resp, 200)
         js = parse_resp(resp)