diff --git a/graphene/types/tests/test_mountedtype.py b/graphene/types/tests/test_mountedtype.py
new file mode 100644
index 00000000..3df7e7fb
--- /dev/null
+++ b/graphene/types/tests/test_mountedtype.py
@@ -0,0 +1,26 @@
+import pytest
+
+from ..mountedtype import MountedType
+from ..field import Field
+from ..scalars import String
+
+
+class CustomField(Field):
+    def __init__(self, *args, **kwargs):
+        self.metadata = kwargs.pop('metadata', None)
+        super(CustomField, self).__init__(*args, **kwargs)
+
+
+def test_mounted_type():
+    unmounted = String()
+    mounted = Field.mount(unmounted)
+    assert isinstance(mounted, Field)
+    assert mounted.type == String
+
+
+def test_mounted_type_custom():
+    unmounted = String(metadata={'hey': 'yo!'})
+    mounted = CustomField.mount(unmounted)
+    assert isinstance(mounted, CustomField)
+    assert mounted.type == String
+    assert mounted.metadata == {'hey': 'yo!'}