diff --git a/appveyor.yml b/appveyor.yml
index 2f5727f..2d2b584 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -28,8 +28,8 @@ environment:
     PYTHON_VERSION: "3.12"
     L2TBINARIES_TRACK: "dev"
     TARGET: wheel
-  - DESCRIPTION: "Run tests on Mac OS with Python 3.12"
-    APPVEYOR_BUILD_WORKER_IMAGE: macos-monterey
+  - DESCRIPTION: "Run tests on Mac OS with Python 3.13"
+    APPVEYOR_BUILD_WORKER_IMAGE: macos-sonoma
     HOMEBREW_NO_INSTALL_CLEANUP: 1
     TARGET: tests
 
diff --git a/config/appveyor/install.sh b/config/appveyor/install.sh
index 93413b9..0ed57e0 100755
--- a/config/appveyor/install.sh
+++ b/config/appveyor/install.sh
@@ -3,5 +3,5 @@
 set -e
 
 brew update -q
-brew install -q gettext gnu-sed python@3.12 snappy tox || true
+brew install -q gettext gnu-sed python@3.13 snappy tox || true
 
diff --git a/config/appveyor/runtests.sh b/config/appveyor/runtests.sh
index 86ba5ce..18cc67c 100755
--- a/config/appveyor/runtests.sh
+++ b/config/appveyor/runtests.sh
@@ -9,7 +9,7 @@ export LDFLAGS="-L/usr/local/lib -L/usr/local/opt/gettext/lib ${LDFLAGS}";
 export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include ${CPPFLAGS}";
 export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib ${LDFLAGS}";
 
-# Set the following environment variables to ensure tox can find Python 3.12.
-export PATH="/usr/local/opt/python@3.12/bin:${PATH}";
+# Set the following environment variables to ensure tox can find Python 3.13.
+export PATH="/usr/local/opt/python@3.13/bin:${PATH}";
 
-tox -e py312
+tox -e py313
diff --git a/setup.cfg b/setup.cfg
index e64676d..5b0d1b0 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = dtformats
-version = 20241013
+version = 20241227
 description = Data formats (dtformats)
 long_description = dtFormats is a collection of various file formats.
 long_description_content_type = text/plain
@@ -69,6 +69,3 @@ exclude =
   tests.*
   utils
 where = .
-
-[bdist_wheel]
-universal = 1