diff --git a/deps_py2.txt b/deps_py2.txt
index 4655a228..c4b07402 100644
--- a/deps_py2.txt
+++ b/deps_py2.txt
@@ -1,3 +1,4 @@
+cython
 numpy
 scipy
 matplotlib
@@ -12,4 +13,4 @@ webtest
 myproxyclient
 esgf-pyclient
 podaacpy
-networkx
\ No newline at end of file
+networkx
diff --git a/deps_py3.txt b/deps_py3.txt
index 05d845c9..60e74279 100644
--- a/deps_py3.txt
+++ b/deps_py3.txt
@@ -1,3 +1,4 @@
+cython
 numpy
 scipy
 matplotlib
@@ -9,4 +10,4 @@ python-dateutil
 mock
 webtest
 podaacpy
-networkx
\ No newline at end of file
+networkx