diff --git a/.cirrus.tasks.yml b/.cirrus.tasks.yml
index f0fbc600b9..e597d8c029 100644
--- a/.cirrus.tasks.yml
+++ b/.cirrus.tasks.yml
@@ -464,6 +464,8 @@ task:
       # Include the OS major version in the cache key.  If the OS image changes
       # to a different major version, we need to reinstall.
       sw_vers -productVersion | sed 's/\..*//'
+      # Also start afresh if we change our MacPorts install script.
+      md5 src/tools/ci/ci_macports_packages.sh
     reupload_on_changes: true
   setup_additional_packages_script: |
     sh src/tools/ci/ci_macports_packages.sh \
diff --git a/src/tools/ci/ci_macports_packages.sh b/src/tools/ci/ci_macports_packages.sh
index 03cbe48a5d..71248bd22b 100755
--- a/src/tools/ci/ci_macports_packages.sh
+++ b/src/tools/ci/ci_macports_packages.sh
@@ -16,13 +16,10 @@ packages="$@"
 macos_major_version="` sw_vers -productVersion | sed 's/\..*//' `"
 echo "macOS major version: $macos_major_version"
 
-# Scan the avialable MacPorts releases to find the latest one for the
-# running macOS release.  By default we assume the first match is the most
-# recent MacPorts version but that can be changed below if it turns out to be
-# problematic or a particular MacPorts release turns out to be broken.
+# Scan the available MacPorts releases to find one that matches the running
+# macOS release.
 macports_release_list_url="https://api.github.com/repos/macports/macports-base/releases"
-macports_version_pattern=".*"
-#macports_version_pattern="2\.9\.3"
+macports_version_pattern="2\.9\.3"
 macports_url="$( curl -s $macports_release_list_url | grep "\"https://github.com/macports/macports-base/releases/download/v$macports_version_pattern/MacPorts-$macports_version_pattern-$macos_major_version-[A-Za-z]*\.pkg\"" | sed 's/.*: "//;s/".*//' | head -1 )"
 echo "MacPorts package URL: $macports_url"