diff --git a/.gitignore b/.gitignore
index ed81f604..8337b46c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -63,5 +63,9 @@ venv/
 .ropeproject/
 
 # C extensions
+src/dependency_injector/*.h
 src/dependency_injector/*.so
+src/dependency_injector/containers/*.h
+src/dependency_injector/containers/*.so
+src/dependency_injector/providers/*.h
 src/dependency_injector/providers/*.so
diff --git a/src/dependency_injector/providers/utils.c b/src/dependency_injector/providers/utils.c
index 4cbf6e99..99e478c0 100644
--- a/src/dependency_injector/providers/utils.c
+++ b/src/dependency_injector/providers/utils.c
@@ -975,7 +975,7 @@ static int __Pyx_InitStrings(__Pyx_StringTabEntry *t);
 
 
 /* Module declarations from 'dependency_injector.providers.utils' */
-__PYX_EXTERN_C DL_EXPORT(PyObject) *__pyx_v_19dependency_injector_9providers_5utils_CLASS_TYPES;
+static PyObject *__pyx_v_19dependency_injector_9providers_5utils_CLASS_TYPES = 0;
 static int __pyx_f_19dependency_injector_9providers_5utils_is_provider(PyObject *, int __pyx_skip_dispatch); /*proto*/
 static PyObject *__pyx_f_19dependency_injector_9providers_5utils_ensure_is_provider(PyObject *, int __pyx_skip_dispatch); /*proto*/
 static int __pyx_f_19dependency_injector_9providers_5utils_is_delegated(PyObject *, int __pyx_skip_dispatch); /*proto*/
@@ -1313,7 +1313,6 @@ static PyObject *__pyx_lambda_funcdef_19dependency_injector_9providers_5utils_la
   __Pyx_RefNannyFinishContext();
   return __pyx_r;
 }
-PyObject *__pyx_v_19dependency_injector_9providers_5utils_CLASS_TYPES = 0;
 
 /* "dependency_injector/providers/utils.pyx":25
  * 
diff --git a/src/dependency_injector/providers/utils.h b/src/dependency_injector/providers/utils.h
deleted file mode 100644
index 00f08d98..00000000
--- a/src/dependency_injector/providers/utils.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* Generated by Cython 0.25.1 */
-
-#ifndef __PYX_HAVE__dependency_injector__providers__utils
-#define __PYX_HAVE__dependency_injector__providers__utils
-
-
-#ifndef __PYX_HAVE_API__dependency_injector__providers__utils
-
-#ifndef __PYX_EXTERN_C
-  #ifdef __cplusplus
-    #define __PYX_EXTERN_C extern "C"
-  #else
-    #define __PYX_EXTERN_C extern
-  #endif
-#endif
-
-#ifndef DL_IMPORT
-  #define DL_IMPORT(_T) _T
-#endif
-
-__PYX_EXTERN_C DL_IMPORT(PyObject) *__pyx_v_19dependency_injector_9providers_5utils_CLASS_TYPES;
-
-#endif /* !__PYX_HAVE_API__dependency_injector__providers__utils */
-
-#if PY_MAJOR_VERSION < 3
-PyMODINIT_FUNC initutils(void);
-#else
-PyMODINIT_FUNC PyInit_utils(void);
-#endif
-
-#endif /* !__PYX_HAVE__dependency_injector__providers__utils */
diff --git a/src/dependency_injector/providers/utils.pxd b/src/dependency_injector/providers/utils.pxd
index 84faf5ba..8c4b49a9 100644
--- a/src/dependency_injector/providers/utils.pxd
+++ b/src/dependency_injector/providers/utils.pxd
@@ -3,7 +3,7 @@
 Powered by Cython.
 """
 
-cdef public object CLASS_TYPES
+cdef object CLASS_TYPES
 
 
 cpdef bint is_provider(object instance)