diff --git a/msal/managed_identity.py b/msal/managed_identity.py
index 181d34c3..608bc1bf 100644
--- a/msal/managed_identity.py
+++ b/msal/managed_identity.py
@@ -40,14 +40,15 @@ class ManagedIdentity(UserDict):
 
     _types_mapping = {  # Maps type name in configuration to type name on wire
         CLIENT_ID: "client_id",
-        RESOURCE_ID: "mi_res_id",
+        RESOURCE_ID: "msi_res_id",  # VM's IMDS prefers msi_res_id https://github.com/Azure/azure-rest-api-specs/blob/dba6ed1f03bda88ac6884c0a883246446cc72495/specification/imds/data-plane/Microsoft.InstanceMetadataService/stable/2018-10-01/imds.json#L233-L239
         OBJECT_ID: "object_id",
     }
 
     @classmethod
     def is_managed_identity(cls, unknown):
-        return isinstance(unknown, ManagedIdentity) or (
-            isinstance(unknown, dict) and cls.ID_TYPE in unknown)
+        return (isinstance(unknown, ManagedIdentity)
+            or cls.is_system_assigned(unknown)
+            or cls.is_user_assigned(unknown))
 
     @classmethod
     def is_system_assigned(cls, unknown):
@@ -217,6 +218,9 @@ def __init__(
                 )
             token = client.acquire_token_for_client("resource")
         """
+        if not ManagedIdentity.is_managed_identity(managed_identity):
+            raise ManagedIdentityError(
+                f"Incorrect managed_identity: {managed_identity}")
         self._managed_identity = managed_identity
         self._http_client = _ThrottledHttpClient(
             # This class only throttles excess token acquisition requests.
@@ -426,9 +430,9 @@ def _obtain_token(http_client, managed_identity, resource):
     return _obtain_token_on_azure_vm(http_client, managed_identity, resource)
 
 
-def _adjust_param(params, managed_identity):
+def _adjust_param(params, managed_identity, types_mapping=None):
     # Modify the params dict in place
-    id_name = ManagedIdentity._types_mapping.get(
+    id_name = (types_mapping or ManagedIdentity._types_mapping).get(
         managed_identity.get(ManagedIdentity.ID_TYPE))
     if id_name:
         params[id_name] = managed_identity[ManagedIdentity.ID]
@@ -475,7 +479,12 @@ def _obtain_token_on_app_service(
         "api-version": "2019-08-01",
         "resource": resource,
         }
-    _adjust_param(params, managed_identity)
+    _adjust_param(params, managed_identity, types_mapping={
+        ManagedIdentity.CLIENT_ID: "client_id",
+        ManagedIdentity.RESOURCE_ID: "mi_res_id",  # App Service's resource id uses "mi_res_id"
+        ManagedIdentity.OBJECT_ID: "object_id",
+    })
+
     resp = http_client.get(
         endpoint,
         params=params,
diff --git a/tests/test_mi.py b/tests/test_mi.py
index 2041419d..1f33fe73 100644
--- a/tests/test_mi.py
+++ b/tests/test_mi.py
@@ -61,6 +61,14 @@ def setUp(self):
             http_client=requests.Session(),
             )
 
+    def test_error_out_on_invalid_input(self):
+        with self.assertRaises(ManagedIdentityError):
+            ManagedIdentityClient({"foo": "bar"}, http_client=requests.Session())
+        with self.assertRaises(ManagedIdentityError):
+            ManagedIdentityClient(
+                {"ManagedIdentityIdType": "undefined", "Id": "foo"},
+                http_client=requests.Session())
+
     def assertCacheStatus(self, app):
         cache = app._token_cache._cache
         self.assertEqual(1, len(cache.get("AccessToken", [])), "Should have 1 AT")
@@ -131,6 +139,22 @@ def test_vm_error_should_be_returned_as_is(self):
                 json.loads(raw_error), self.app.acquire_token_for_client(resource="R"))
             self.assertEqual({}, self.app._token_cache._cache)
 
+    def test_vm_resource_id_parameter_should_be_msi_res_id(self):
+        app = ManagedIdentityClient(
+            {"ManagedIdentityIdType": "ResourceId", "Id": "1234"},
+            http_client=requests.Session(),
+            )
+        with patch.object(app._http_client, "get", return_value=MinimalResponse(
+            status_code=200,
+            text='{"access_token": "AT", "expires_in": 3600, "resource": "R"}',
+        )) as mocked_method:
+            app.acquire_token_for_client(resource="R")
+            mocked_method.assert_called_with(
+                'http://169.254.169.254/metadata/identity/oauth2/token',
+                params={'api-version': '2018-02-01', 'resource': 'R', 'msi_res_id': '1234'},
+                headers={'Metadata': 'true'},
+                )
+
 
 @patch.dict(os.environ, {"IDENTITY_ENDPOINT": "http://localhost", "IDENTITY_HEADER": "foo"})
 class AppServiceTestCase(ClientTestCase):
@@ -156,6 +180,22 @@ def test_app_service_error_should_be_normalized(self):
             }, self.app.acquire_token_for_client(resource="R"))
             self.assertEqual({}, self.app._token_cache._cache)
 
+    def test_app_service_resource_id_parameter_should_be_mi_res_id(self):
+        app = ManagedIdentityClient(
+            {"ManagedIdentityIdType": "ResourceId", "Id": "1234"},
+            http_client=requests.Session(),
+            )
+        with patch.object(app._http_client, "get", return_value=MinimalResponse(
+            status_code=200,
+            text='{"access_token": "AT", "expires_on": 12345, "resource": "R"}',
+        )) as mocked_method:
+            app.acquire_token_for_client(resource="R")
+            mocked_method.assert_called_with(
+                'http://localhost',
+                params={'api-version': '2019-08-01', 'resource': 'R', 'mi_res_id': '1234'},
+                headers={'X-IDENTITY-HEADER': 'foo', 'Metadata': 'true'},
+                )
+
 
 @patch.dict(os.environ, {"MSI_ENDPOINT": "http://localhost", "MSI_SECRET": "foo"})
 class MachineLearningTestCase(ClientTestCase):
@@ -241,6 +281,9 @@ class ArcTestCase(ClientTestCase):
         "WWW-Authenticate": "Basic realm=/tmp/foo",
         })
 
+    def test_error_out_on_invalid_input(self, mocked_stat):
+        return super(ArcTestCase, self).test_error_out_on_invalid_input()
+
     def test_happy_path(self, mocked_stat):
         expires_in = 1234
         with patch.object(self.app._http_client, "get", side_effect=[