diff --git a/synthtool/gcp/templates/python_library/noxfile.py.j2 b/synthtool/gcp/templates/python_library/noxfile.py.j2
index 5dab01ef8..aa66e4264 100644
--- a/synthtool/gcp/templates/python_library/noxfile.py.j2
+++ b/synthtool/gcp/templates/python_library/noxfile.py.j2
@@ -350,7 +350,16 @@ def docs(session):
 
     session.install("-e", ".")
     session.install(
-        "sphinx==4.0.1",
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
+        "sphinx==4.5.0",
         "alabaster",
         "recommonmark",
     )
@@ -376,6 +385,15 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "gcp-sphinx-docfx-yaml",
         "alabaster",
         "recommonmark",
diff --git a/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2 b/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
index e2b051308..105478286 100644
--- a/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
+++ b/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
@@ -359,6 +359,15 @@ def docs(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "sphinx==4.5.0",
         "alabaster",
         "recommonmark",
@@ -385,6 +394,15 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "gcp-sphinx-docfx-yaml",
         "alabaster",
         "recommonmark",