diff --git a/CONTRIBUTING.txt b/CONTRIBUTING.txt
index 29dba55d..38bb784d 100644
--- a/CONTRIBUTING.txt
+++ b/CONTRIBUTING.txt
@@ -77,6 +77,8 @@ For a more detailed discussion, read these :doc:`detailed documents
      Travis fails, you can find out why by clicking on the "failed" icon (red
      cross) and inspecting the build and test log.
 
+   * A pull request must be approved by two core team members before merging.
+
 5. Document changes
 
    If your change introduces any API modifications, please update
@@ -127,7 +129,8 @@ Guidelines
 * All code should be documented, to the same
   `standard <https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt#docstring-standard>`_ as NumPy and SciPy.
 * For new functionality, always add an example to the gallery.
-* No changes are ever committed without review.  Ask on the
+* No changes are ever committed without review and approval by two core
+  team members.  Ask on the
   `mailing list <http://groups.google.com/group/scikit-image>`_ if
   you get no response to your pull request.
   **Never merge your own pull request.**