Fix the issue

src/dependency_injector/containers.c

@@ -915,12 +915,12 @@ struct __pyx_obj_19dependency_injector_9providers_Delegate {
  * 
  * 
  * cdef class Dependency(Provider):             # <<<<<<<<<<<<<<
- *     cdef type __instance_of
+ *     cdef object __instance_of
  * 
  */
 struct __pyx_obj_19dependency_injector_9providers_Dependency {
   struct __pyx_obj_19dependency_injector_9providers_Provider __pyx_base;
-  PyTypeObject *__pyx___instance_of;
+  PyObject *__pyx___instance_of;
 };
 
 
@@ -1485,7 +1485,7 @@ static struct __pyx_vtabstruct_19dependency_injector_9providers_Delegate *__pyx_
  * 
  * 
  * cdef class Dependency(Provider):             # <<<<<<<<<<<<<<
- *     cdef type __instance_of
+ *     cdef object __instance_of
  * 
  */
 

src/dependency_injector/providers.pxd

@@ -28,7 +28,7 @@ cdef class Delegate(Provider):
 
 
 cdef class Dependency(Provider):
-    cdef type __instance_of
+    cdef object __instance_of
 
 
 cdef class ExternalDependency(Dependency):

src/dependency_injector/providers.pyx

@@ -419,8 +419,16 @@ cdef class Dependency(Provider):
         :type: type
    """
 
-    def __init__(self, type instance_of=object):
+    def __init__(self, object instance_of=object):
         """Initializer."""
+        if not isinstance(instance_of, CLASS_TYPES):
+            raise TypeError(
+                'Argument \'instance_of\' has incorrect type (expected {0}, got {1}))'.format(
+                    CLASS_TYPES,
+                    instance_of,
+                )
+            )
+
         self.__instance_of = instance_of
         super(Dependency, self).__init__()