diff --git a/github_issue_summarization/requirements.txt b/github_issue_summarization/requirements.txt
index 8440ddbd2..b1ff8a8ae 100644
--- a/github_issue_summarization/requirements.txt
+++ b/github_issue_summarization/requirements.txt
@@ -37,7 +37,7 @@ contextlib2==0.5.5
 cryptography==2.0.3
 cycler==0.10.0
 cymem==1.31.2
-Cython==0.26.1
+Cython==0.29.32
 cytoolz==0.9.0
 dask==0.16.1
 datashape==0.5.4