diff --git a/doc/requirements.txt b/doc/requirements.txt
index ff2ea3c..c9d1fc9 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,4 +1,4 @@
-antlr4-python3-runtime>=4.7.1
+antlr4-python3-runtime==4.9.2
 numpy
 sphinxcontrib-bibtex<2.0.0
 breathe~=4.29.0