diff --git a/requirements/devel.txt b/requirements/devel.txt
index 17f3707ae..78936bc0e 100644
--- a/requirements/devel.txt
+++ b/requirements/devel.txt
@@ -16,6 +16,7 @@ pytest-timeout
 
 sphinx==2.2.0 ; python_version >= '3.0'
 sphinx==1.8.5 ; python_version < '3.0'
+sphinxcontrib-applehelp<1.0.8
 Jinja2==2.10
 markupsafe==1.1.1
 doc2dash==2.3.0