diff --git a/requirements.txt b/requirements.txt
index 75b03c139..45c9c1011 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
-pandas==0.20.3
+Cython==0.29.14
+pandas==0.23.3
 simplejson==3.11.1
 boto3==1.9.134
 scikit-learn==0.21.1; python_version >= '3.5'