diff --git a/.librarian/generator-input/noxfile.py b/.librarian/generator-input/noxfile.py
index 4fb209cbc..6b22aa7a4 100644
--- a/.librarian/generator-input/noxfile.py
+++ b/.librarian/generator-input/noxfile.py
@@ -71,6 +71,7 @@
 SYSTEM_TEST_EXTERNAL_DEPENDENCIES: List[str] = [
     "pytest-asyncio==0.21.2",
     "six",
+    "pyyaml",
 ]
 SYSTEM_TEST_LOCAL_DEPENDENCIES: List[str] = []
 SYSTEM_TEST_DEPENDENCIES: List[str] = []
@@ -80,7 +81,6 @@
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
 nox.options.sessions = [
-    "unit-3.9",
     "unit-3.10",
     "unit-3.11",
     "unit-3.12",