diff --git a/requirements.txt b/requirements.txt
index 32dfa74..c9a19f5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 mkdocs>=0.17.5
 mkdocs-material==2.9.4 
-pymdown-extensions
+pymdown-extensions==5.0
 Markdown==2.6.11