diff --git a/.github/workflows/continuous-integration.yaml b/.github/workflows/continuous-integration.yaml
index 18cdf1d..b2b19be 100644
--- a/.github/workflows/continuous-integration.yaml
+++ b/.github/workflows/continuous-integration.yaml
@@ -11,7 +11,7 @@ jobs:
   run-testsuite:
     strategy:
       matrix:
-        os: ['ubuntu-latest', 'macos-13', 'macos-14']
+        os: ['ubuntu-latest', 'macos-13', 'macos-14', 'macos-15']
     runs-on: '${{ matrix.os }}'
     name: 'Run Testsuite'
     steps:
@@ -22,12 +22,12 @@ jobs:
   install-macports:
     strategy:
       matrix:
-        os: ['macos-13', 'macos-14']
-        version: ['2.9.3']
+        os: ['macos-13', 'macos-14', 'macos-15']
+        version: ['2.11.5']
         prefix: ['local']
         include:
           - os: 'macos-14'
-            version: '2.9.3'
+            version: '2.11.5'
             prefix: 'package'
     runs-on: '${{ matrix.os }}'
     name: 'Install MacPorts'
@@ -47,6 +47,7 @@ jobs:
       - name: 'Validate transmitted MacPorts prefix'
         run: >-
           test "${{ steps.macports.outputs.prefix }}" = '/opt/${{ matrix.prefix }}'
+
       - name: 'Validate transmitted MacPorts version'
         run: >-
           test "${{ steps.macports.outputs.version }}" = '${{ matrix.version }}'
diff --git a/README.md b/README.md
index 2671b40..8b1e060 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ to get started with GitHub workflows.
 
 The configuration file is in YAML and has the following format:
 
-* `version: '2.9.3'` — The MacPorts version to install.
+* `version: '2.11.5'` — The MacPorts version to install.
 * `prefix: '/opt/local'` — The installation prefix to install MacPorts to.
   The default is `/opt/local` and only needs to be changed when
   preparing self-install packages for instane.
@@ -81,35 +81,35 @@ on:
   - push
 
 jobs:
-  install-macports-on-macos-11:
-    runs-on: macos-11
-    name: 'Install MacPorts 2.9.3 on MacOS 11'
+  install-macports-on-macos-13:
+    runs-on: macos-13
+    name: 'Install MacPorts 2.11.5 on MacOS 13'
     steps:
       - uses: actions/checkout@v3
       - uses: paranext/setup-macports@v1
         id: 'macports'
         with:
-          parameters: 'testsuite/run-testsuite-on-macos-11.yaml'
+          parameters: 'testsuite/run-testsuite-on-macos-13.yaml'
       - name: 'Validate installed MacPorts version'
         run: >-
-          test "$(port version)" = 'Version: 2.9.3'
+          test "$(port version)" = 'Version: 2.11.5'
       - name: 'Validate transmitted MacPorts prefix'
         run: >-
           test "${{ steps.macports.outputs.prefix }}" = '/opt/local'
       - name: 'Validate transmitted MacPorts version'
         run: >-
-          test "${{ steps.macports.outputs.version }}" = '2.9.3'
+          test "${{ steps.macports.outputs.version }}" = '2.11.5'
 
-  install-macports-on-macos-12:
-    runs-on: macos-12
-    name: 'Install MacPorts 2.9.3 on MacOS 12'
+  install-macports-on-macos-14:
+    runs-on: macos-14
+    name: 'Install MacPorts 2.11.5 on MacOS 14'
     steps:
       - uses: actions/checkout@v3
       - name: 'Run testsuite'
         run: development/testsuite
       - uses: paranext/setup-macports@v1
         with:
-          parameters: 'testsuite/run-testsuite-on-macos-12.yaml'
+          parameters: 'testsuite/run-testsuite-on-macos-14.yaml'
       - run: port version
 ```
 
@@ -117,7 +117,7 @@ jobs:
 ## Example parameters
 
 ```yaml
-version: '2.9.3'
+version: '2.11.5'
 prefix: '/opt/local'
 variants:
   select:
diff --git a/action.yaml b/action.yaml
index 2b22ae0..b5f5f74 100644
--- a/action.yaml
+++ b/action.yaml
@@ -17,7 +17,7 @@ inputs:
       
       The configuration file is in YAML and has the following format:
 
-        version: '2.9.3'
+        version: '2.11.5'
           The MacPorts version to install.
         prefix: '/opt/local'
           The installation prefix to install MacPortd to.
diff --git a/subr/macos.sh b/subr/macos.sh
index 99f34ce..4faaf7c 100644
--- a/subr/macos.sh
+++ b/subr/macos.sh
@@ -41,6 +41,7 @@ known_macos_db()
 12-Monterey
 13-Ventura
 14-Sonoma
+15-Sequoia
 EOF
 }
 
diff --git a/subr/macports.sh b/subr/macports.sh
index f52494d..8e32004 100644
--- a/subr/macports.sh
+++ b/subr/macports.sh
@@ -14,7 +14,7 @@
 
 : ${macports_owner:=$(id -u -n)}
 : ${macports_group:=$(id -g -n)}
-: ${macports_version:='2.9.3'}
+: ${macports_version:='2.11.5'}
 : ${macports_prefix:='/opt/local'}
 
 macports_install()
diff --git a/testsuite/run-testsuite-on-macos-13-local.yaml b/testsuite/run-testsuite-on-macos-13-local.yaml
index 98f96bc..52ef425 100644
--- a/testsuite/run-testsuite-on-macos-13-local.yaml
+++ b/testsuite/run-testsuite-on-macos-13-local.yaml
@@ -1,4 +1,4 @@
-version: '2.9.3'
+version: '2.11.5'
 prefix: '/opt/local'
 variants:
   select:
diff --git a/testsuite/run-testsuite-on-macos-14-local.yaml b/testsuite/run-testsuite-on-macos-14-local.yaml
index 45590cb..61e8c79 100644
--- a/testsuite/run-testsuite-on-macos-14-local.yaml
+++ b/testsuite/run-testsuite-on-macos-14-local.yaml
@@ -1,4 +1,4 @@
-version: '2.9.3'
+version: '2.11.5'
 prefix: '/opt/local'
 variants:
   select:
diff --git a/testsuite/run-testsuite-on-macos-14-package.yaml b/testsuite/run-testsuite-on-macos-14-package.yaml
index 166d40c..68e0d9b 100644
--- a/testsuite/run-testsuite-on-macos-14-package.yaml
+++ b/testsuite/run-testsuite-on-macos-14-package.yaml
@@ -1,4 +1,4 @@
-version: '2.9.3'
+version: '2.11.5'
 prefix: '/opt/package'
 variants:
   select:
diff --git a/testsuite/run-testsuite-on-macos-12-local.yaml b/testsuite/run-testsuite-on-macos-15-local.yaml
similarity index 85%
rename from testsuite/run-testsuite-on-macos-12-local.yaml
rename to testsuite/run-testsuite-on-macos-15-local.yaml
index 98f96bc..4a13f76 100644
--- a/testsuite/run-testsuite-on-macos-12-local.yaml
+++ b/testsuite/run-testsuite-on-macos-15-local.yaml
@@ -1,4 +1,4 @@
-version: '2.9.3'
+version: '2.11.5'
 prefix: '/opt/local'
 variants:
   select:
@@ -11,4 +11,4 @@ ports:
     select: [ tcl, universal ]
   - name: gmp
     select: native
-  - name: dbus
+  - name: dbus
\ No newline at end of file
diff --git a/testsuite/run-testsuite-on-macos-15-package.yaml b/testsuite/run-testsuite-on-macos-15-package.yaml
new file mode 100644
index 0000000..68e0d9b
--- /dev/null
+++ b/testsuite/run-testsuite-on-macos-15-package.yaml
@@ -0,0 +1,16 @@
+version: '2.11.5'
+prefix: '/opt/package'
+variants:
+  select:
+    - aqua
+    - metal
+    - python312
+  deselect: x11
+ports:
+  - name: db48
+    deselect: [ java ]
+    select: [ tcl, universal ]
+  - name: gmp
+    select: native
+  - name: dbus
+  - name: curl