diff --git a/docs/requirements.txt b/docs/requirements.txt
index 25d6e174d0..eeb70a317e 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -20,7 +20,7 @@ sphinx-favicon==1.0.1
 sphinx-rtd-theme==1.2.2
 sphinxcontrib-applehelp==1.0.7
 sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-serializinghtml==1.1.9
 sphinxcontrib-htmlhelp==2.0.1
 sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.6