diff --git a/natural-language-processing/docker/requirements.txt b/natural-language-processing/docker/requirements.txt
index 77df8f9..a678a03 100644
--- a/natural-language-processing/docker/requirements.txt
+++ b/natural-language-processing/docker/requirements.txt
@@ -30,7 +30,7 @@ libarchive==0.4.4
 Markdown==2.6.9
 MarkupSafe==1.0
 matplotlib==2.1.0
-mistune==0.8.1
+mistune==2.0.3
 mock==2.0.0
 nbconvert==5.3.1
 nbformat==4.4.0