diff --git a/tools/pinning/pyproject.toml b/tools/pinning/pyproject.toml
index 20a1f3bf2..34fea18a6 100644
--- a/tools/pinning/pyproject.toml
+++ b/tools/pinning/pyproject.toml
@@ -35,6 +35,13 @@ acme = {path = "../../acme", extras = ["dev", "docs"]}
 windows-installer = {path = "../../windows-installer"}
 
 # Extra dependencies
+# As of writing this, cython is a build dependency of pyyaml. Since there
+# doesn't appear to be a good way to automatically track down and pin build
+# dependencies in Python (see
+# https://discuss.python.org/t/how-to-pin-build-dependencies/8238), we list it
+# as a dependency here to ensure a version of cython is pinned for extra
+# stability.
+cython = "*"
 # We install mock in our "external-mock" tox environment to test that we didn't
 # break Certbot's test API which used to always use mock objects from the 3rd
 # party mock library. We list the mock dependency here so that is pinned, but
diff --git a/tools/requirements.txt b/tools/requirements.txt
index 498c1e87a..b662744c6 100644
--- a/tools/requirements.txt
+++ b/tools/requirements.txt
@@ -18,8 +18,8 @@ backcall==0.2.0
 bcrypt==3.2.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 beautifulsoup4==4.9.3; python_version >= "3.6" and python_version < "4.0"
 bleach==3.3.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
-boto3==1.17.47; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
-botocore==1.20.47; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
+boto3==1.17.53; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
+botocore==1.20.53; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
 cachecontrol==0.12.6; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 cached-property==1.5.2; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.4.0" and python_version >= "3.6"
 cachetools==4.2.1; python_version >= "3.5" and python_version < "4.0" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6")
@@ -36,7 +36,8 @@ configobj==5.0.6; python_version >= "3.6"
 coverage==4.5.4; (python_version >= "2.6" and python_full_version < "3.0.0") or (python_full_version >= "3.3.0" and python_version < "4")
 crashtest==0.3.1; python_version >= "3.6" and python_version < "4.0" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0")
 cryptography==3.4.7; python_version >= "3.6" and python_full_version < "3.0.0" and python_version < "4.0" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0") and sys_platform == "linux" or python_full_version >= "3.5.0" and python_version >= "3.6" and python_version < "4.0" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0") and sys_platform == "linux"
-decorator==5.0.6
+cython==0.29.23; (python_version >= "2.6" and python_full_version < "3.0.0") or (python_full_version >= "3.3.0")
+decorator==5.0.7
 deprecated==1.2.12; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.4.0"
 distlib==0.3.1; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 distro==1.5.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.4.0" and python_version >= "3.6"
@@ -51,9 +52,9 @@ execnet==1.8.0; python_version >= "3.6" and python_full_version < "3.0.0" or pyt
 filelock==3.0.12; python_version >= "3.6" and python_full_version < "3.0.0" and python_version < "4.0" or python_version >= "3.6" and python_full_version >= "3.5.0" and python_version < "4.0"
 future==0.18.2; python_version >= "3.6" and python_full_version < "3.0.0" and python_version < "4.0" or python_version >= "3.6" and python_version < "4.0" and python_full_version >= "3.3.0"
 google-api-core==1.26.3; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
-google-api-python-client==2.1.0; python_version >= "3.6"
+google-api-python-client==2.2.0; python_version >= "3.6"
 google-auth-httplib2==0.1.0; python_version >= "3.6"
-google-auth==1.28.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
+google-auth==1.29.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
 googleapis-common-protos==1.53.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
 html5lib==1.1; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 httplib2==0.19.1; python_version >= "3.6"
@@ -97,8 +98,8 @@ pickleshare==0.7.5
 pkginfo==1.7.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 pluggy==0.13.1; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 ply==3.11; python_version >= "3.6"
-poetry-core==1.0.2; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
-poetry==1.1.5; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
+poetry-core==1.0.3; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
+poetry==1.1.6; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 prompt-toolkit==3.0.3
 protobuf==3.15.8; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
 ptyprocess==0.7.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
@@ -139,14 +140,14 @@ requests-toolbelt==0.9.1; python_version >= "3.6" and python_full_version < "3.0
 requests==2.25.1; python_version >= "3.6" and python_full_version < "3.0.0" and python_version < "4.0" or python_version >= "3.6" and python_full_version >= "3.6.0" and python_version < "4.0"
 rfc3986==1.4.0; python_version >= "3.6"
 rsa==4.7.2; python_version >= "3.6" and python_version < "4" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6")
-s3transfer==0.3.6; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
+s3transfer==0.3.7; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version >= "3.6"
 secretstorage==3.3.1; python_version >= "3.6" and python_version < "4.0" and (python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0") and sys_platform == "linux"
 shellingham==1.4.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.5.0"
 six==1.15.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 snowballstemmer==2.1.0; python_version >= "3.6"
 soupsieve==2.2.1; python_version >= "3.6"
 sphinx-rtd-theme==0.5.2; python_version >= "3.6"
-sphinx==3.5.3; python_version >= "3.6"
+sphinx==3.5.4; python_version >= "3.6"
 sphinxcontrib-applehelp==1.0.2; python_version >= "3.6"
 sphinxcontrib-devhelp==1.0.2; python_version >= "3.6"
 sphinxcontrib-htmlhelp==1.0.3; python_version >= "3.6"
@@ -161,7 +162,7 @@ tox==3.23.0; python_version >= "3.6" and python_full_version < "3.0.0" or python
 tqdm==4.60.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_version >= "3.6" and python_full_version >= "3.4.0"
 traitlets==4.3.3
 twine==3.3.0; python_version >= "3.6"
-typed-ast==1.4.2; implementation_name == "cpython" and python_version < "3.8" and python_version >= "3.6"
+typed-ast==1.4.3; implementation_name == "cpython" and python_version < "3.8" and python_version >= "3.6"
 typing-extensions==3.7.4.3; python_version >= "3.6"
 uritemplate==3.0.1; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.4.0" and python_version >= "3.6"
 urllib3==1.26.4; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.6.0" and python_version < "4" and python_version >= "3.6"
@@ -175,7 +176,7 @@ zipp==3.4.1; python_version >= "3.6" and python_full_version < "3.0.0" and pytho
 zope.component==5.0.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 zope.event==4.5.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 zope.hookable==5.0.1; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
-zope.interface==5.3.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
+zope.interface==5.4.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 pip==20.2.4
 setuptools==54.1.2
 wheel==0.35.1