diff --git a/setup.py b/setup.py
index 56c753ea..cb684564 100644
--- a/setup.py
+++ b/setup.py
@@ -6,6 +6,10 @@ import re
 from setuptools import setup, Extension
 
 
+# Defining setup variables:
+defined_macros = list()
+package_data = dict([('dependency_injector', ['*.pxd'])])
+
 # Getting description:
 with open('README.rst') as readme_file:
     description = readme_file.read()
@@ -18,12 +22,14 @@ with open('requirements.txt') as version:
 with open('src/dependency_injector/__init__.py') as init_file:
     version = re.search('VERSION = \'(.*?)\'', init_file.read()).group(1)
 
-# Defining macros:
-defined_macros = list()
+# Adding debug options:
 if os.environ.get('DEPENDENCY_INJECTOR_DEBUG_MODE') == '1':
     defined_macros.append(('CYTHON_TRACE', 1))
     defined_macros.append(('CYTHON_TRACE_NOGIL', 1))
 
+    package_data['dependency_injector'].append('*.pyx')
+    package_data['dependency_injector'].append('*.c')
+
 
 setup(name='dependency-injector',
       version=version,
@@ -49,9 +55,7 @@ setup(name='dependency-injector',
                     define_macros=defined_macros,
                     extra_compile_args=['-O2']),
       ],
-      package_data={
-          'dependency_injector': ['*.pxd']
-      },
+      package_data=package_data,
       zip_safe=True,
       license='BSD New',
       platforms=['any'],