diff --git a/numpy/distutils/command/egg_info.py b/numpy/distutils/command/egg_info.py
index b7104de5be40..972a27df3846 100644
--- a/numpy/distutils/command/egg_info.py
+++ b/numpy/distutils/command/egg_info.py
@@ -1,9 +1,17 @@
 from __future__ import division, absolute_import, print_function
 
+import sys
+
 from setuptools.command.egg_info import egg_info as _egg_info
 
 class egg_info(_egg_info):
     def run(self):
+        if 'sdist' in sys.argv:
+            import warnings
+            warnings.warn("`build_src` is being run, this may lead to missing "
+                          "files in your sdist!  See numpy issue gh-7127 for "
+                          "details", UserWarning)
+
         # We need to ensure that build_src has been executed in order to give
         # setuptools' egg_info command real filenames instead of functions which
         # generate files.
diff --git a/setup.py b/setup.py
index ded914b11dc4..276d7e5ead30 100755
--- a/setup.py
+++ b/setup.py
@@ -188,7 +188,7 @@ def check_submodules():
             raise ValueError('Submodule not clean: %s' % line)
 
 
-from setuptools.command.sdist import sdist
+from distutils.command.sdist import sdist
 class sdist_checked(sdist):
     """ check submodules on sdist to prevent incomplete tarballs """
     def run(self):