diff --git a/pyproject.toml b/pyproject.toml
index 682c20d..7779c65 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -45,7 +45,7 @@ classifiers = [
 dependencies = [
     # mcp 2.x removed `mcp.server.fastmcp`; pin <2.0 until we adapt to the new API.
     "mcp>=1.6.0,<2.0",
-    "pyyaml>=6.0",
+    "pyyaml>=6.0.3",
     "tomli>=2.0.0; python_version<'3.11'",
 ]
 
diff --git a/requirements.txt b/requirements.txt
index 083c5bd..af5dddb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,5 +3,5 @@
 # server parses Python with the standard-library `ast` module.
 # mcp 2.x removed `mcp.server.fastmcp`; pin <2.0 until we adapt to the new API.
 mcp>=1.6.0,<2.0
-pyyaml>=6.0
+pyyaml>=6.0.3
 tomli>=2.0.0; python_version<"3.11"