diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 53c66677..c9957d9f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,18 +16,28 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: [ '8', '11', '16', '17', '19' ]
-        runs-on: [ubuntu-latest, macos-latest, windows-latest]
+        java: [ '8', '11', '16', '17', '19', '21' ]
+        runs-on: [ubuntu-latest, macos-12, windows-latest]
+        exclude:
+          - runs-on: macos-latest
+            java: "8"
+          - runs-on: macos-latest
+            java: "16"
 
     name: Test on Java ${{ matrix.Java }} on ${{ matrix.runs-on }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up JDK ${{ matrix.Java }}
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@v4
       with:
         java-version: ${{ matrix.Java }}
         distribution: 'temurin'
 
+    - name: Install HDF5 on macos-latest (v14)
+      if: ${{ matrix.runs-on == 'macos-latest' }}
+      run: |
+        brew install hdf5
+
     - name: Install and test (non Win)
       env:
         main_repo_branch: ${GITHUB_REF_NAME}
diff --git a/.github/workflows/javadocs.yml b/.github/workflows/javadocs.yml
index df4fda2e..226a1cde 100644
--- a/.github/workflows/javadocs.yml
+++ b/.github/workflows/javadocs.yml
@@ -9,16 +9,17 @@ jobs:
 
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Set up JDK 17
-      uses: actions/setup-java@v1
+      uses: actions/setup-java@v4
       with:
         java-version: 17
         java-package: jdk
+        distribution: 'temurin'
 
     - name: Set up Python 3.9
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
         python-version: 3.9
 
@@ -28,14 +29,14 @@ jobs:
         pip install ghp-import
 
     - name: Checkout NeuroML2
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         repository: NeuroML/NeuroML2
         ref: development
         path: NeuroML2
 
     - name: Checkout org.neuroml.model.injectingplugin
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         repository: NeuroML/org.neuroml.model.injectingplugin
         ref: development
diff --git a/pom.xml b/pom.xml
index 66d5f1b8..6d88b38f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -158,8 +158,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.0</version>
                 <configuration>
-                    <source>1.7</source>
-                    <target>1.7</target>
+                    <source>1.8</source>
+                    <target>1.8</target>
                 </configuration>
             </plugin>
             <plugin>