diff --git a/doc/requirements.txt b/doc/requirements.txt
index db07feb2..3f3c68f2 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -4,7 +4,7 @@
 
 sphinx>=2.0.0,!=2.1.0 # BSD
 sphinxcontrib-svg2pdfconverter>=0.1.0 # BSD
-sphinxcontrib-mermaid>=0.3.1 # BSD
+sphinxcontrib-mermaid>=0.3.1,!=0.6.1 # BSD
 requests
 pyquery