diff --git a/DEPENDS.txt b/DEPENDS.txt
index aa3cd021..02ee007f 100644
--- a/DEPENDS.txt
+++ b/DEPENDS.txt
@@ -2,7 +2,7 @@ Build Requirements
 ------------------
 * `Python >= 2.6 <http://python.org>`__
 * `Numpy >= 1.6 <http://numpy.scipy.org/>`__
-* `Cython >= 0.19.2 <http://www.cython.org/>`__
+* `Cython >= 0.21 <http://www.cython.org/>`__
 * `Six >=1.3 <https://pypi.python.org/pypi/six>`__
 
 You can use pip to automatically install the base dependencies as follows::
diff --git a/requirements.txt b/requirements.txt
index 189b627b..12ce5fc6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-cython>=0.19.2
+cython>=0.21
 matplotlib>=1.1.0
 numpy>=1.6.1
 scipy>=0.9