diff --git a/setup.py b/setup.py
index f8feb7ebcae..ae793554010 100644
--- a/setup.py
+++ b/setup.py
@@ -48,6 +48,7 @@
         "json-rpc",
         "Jinja2 >= 2.11", # I need "include" and auto-context + blank line are not indented by default
         "pyyaml",
+        "mistune < 2.0.0",
         "m2r",
         "black",
     ],