diff --git a/tools/ontology-builder/requirements.txt b/tools/ontology-builder/requirements.txt
index 07a8d742..ed7a90ab 100644
--- a/tools/ontology-builder/requirements.txt
+++ b/tools/ontology-builder/requirements.txt
@@ -1,2 +1,2 @@
 owlready2==0.38
-PyYaml==6.0
\ No newline at end of file
+PyYaml==6.0.1
\ No newline at end of file