diff --git a/.github/workflows/daily.yml b/.github/workflows/daily.yml
index 0abd07732e88..28f0874872e3 100644
--- a/.github/workflows/daily.yml
+++ b/.github/workflows/daily.yml
@@ -68,9 +68,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          # TODO: Use Python 3.12. As of 2024-03-08, several third-party
-          # packages fail to install with Python 3.12.
-          python-version: "3.11"
+          python-version: "3.12"
           cache: pip
           cache-dependency-path: |
             requirements-tests.txt
diff --git a/.github/workflows/stubtest_third_party.yml b/.github/workflows/stubtest_third_party.yml
index 91eb3c51b1cb..21c2a0b8b6de 100644
--- a/.github/workflows/stubtest_third_party.yml
+++ b/.github/workflows/stubtest_third_party.yml
@@ -43,9 +43,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          # TODO: Use Python 3.12. As of 2024-03-08, several third-party
-          # packages fail to install with Python 3.12.
-          python-version: "3.11"
+          python-version: "3.12"
           cache: pip
           cache-dependency-path: |
             requirements-tests.txt
diff --git a/stubs/atheris/METADATA.toml b/stubs/atheris/METADATA.toml
index 5a014d0c8f63..52458d522e5a 100644
--- a/stubs/atheris/METADATA.toml
+++ b/stubs/atheris/METADATA.toml
@@ -4,3 +4,6 @@ partial_stub = true
 
 [tool.stubtest]
 ignore_missing_stub = true
+# TODO: Does not compile with Python 3.12 as of 2024-10-18 (release 2.3.0).
+# https://github.com/google/atheris/pull/60
+skip = true
diff --git a/stubs/gdb/METADATA.toml b/stubs/gdb/METADATA.toml
index 8aa64fa66bab..6d126b461643 100644
--- a/stubs/gdb/METADATA.toml
+++ b/stubs/gdb/METADATA.toml
@@ -13,3 +13,16 @@ extra_description = """\
 [tool.stubtest]
 platforms = ["linux"]
 apt_dependencies = ["gdb"]
+# stubtest fails for unknown reasons after upgrading to use Python 3.12:
+#
+# Traceback (most recent call last):
+#   File "/tmp/stubtest-4m851njl/gdb_stubtest.py", line 22, in <module>
+#     from mypy.stubtest import main
+#   File "/tmp/stubtest-4m851njl/lib/python3.12/site-packages/mypy/stubtest.py", line 30, in <module>
+#     from pathlib import Path
+#   File "/usr/lib/python3.12/pathlib.py", line 19, in <module>
+#     from urllib.parse import quote_from_bytes as urlquote_from_bytes
+#   File "/usr/lib/python3.12/urllib/parse.py", line 36, in <module>
+#     import math
+# ModuleNotFoundError: No module named 'math'
+skip = true
diff --git a/stubs/openpyxl/@tests/stubtest_allowlist.txt b/stubs/openpyxl/@tests/stubtest_allowlist.txt
index 1a9bcaf7b121..d548945f4d0c 100644
--- a/stubs/openpyxl/@tests/stubtest_allowlist.txt
+++ b/stubs/openpyxl/@tests/stubtest_allowlist.txt
@@ -195,7 +195,3 @@ openpyxl.worksheet.smart_tag.CellSmartTagPr.__init__
 openpyxl.worksheet.smart_tag.CellSmartTags.__init__
 openpyxl.worksheet.table.TableColumn.__init__
 openpyxl.worksheet.table.XMLColumnProps.__init__
-
-# Inherited from the stdlib, where we lie about the presence
-# of this method in order to mark it as deprecated.
-openpyxl.xml.functions.Element.__bool__
diff --git a/stubs/requests/@tests/stubtest_allowlist.txt b/stubs/requests/@tests/stubtest_allowlist.txt
index 667b6b8ae327..3bfd86463261 100644
--- a/stubs/requests/@tests/stubtest_allowlist.txt
+++ b/stubs/requests/@tests/stubtest_allowlist.txt
@@ -2,6 +2,3 @@
 requests.packages.mod
 requests.packages.package
 requests.packages.target
-
-# Alias for builtins.bytes
-requests.compat.bytes.__buffer__