diff --git a/tools/serve_header/requirements.txt b/tools/serve_header/requirements.txt
index d32eed3bd..68fb9527d 100644
--- a/tools/serve_header/requirements.txt
+++ b/tools/serve_header/requirements.txt
@@ -1,2 +1,2 @@
-PyYAML==6.0
+PyYAML==6.0.2
 watchdog==2.1.7