diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 60c0b0b85a..06428c2abd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,9 +15,9 @@ defaults:
     shell: bash
 
 env:
-  JAVA_VERSION: 21 # must be consistent with POM; see also dependabot config for any version limits
+  JAVA_VERSION: 25 # must be consistent with POM; see also dependabot config for any version limits
   JAVA_VERSION_LATEST: 25 # the latest `JAVA_VERSION` that we test with CI
-  java_distribution: zulu
+  java_distribution: temurin
   groovy_version: 4.x
   CCDB_CONNECTION: 'sqlite:///${{ github.workspace }}/coatjava/etc/data/sqlite/ccdb.sqlite'
   RCDB_CONNECTION: 'sqlite:///${{ github.workspace }}/coatjava/etc/data/sqlite/rcdb.sqlite'
@@ -81,7 +81,7 @@ jobs:
           key: ${{ steps.key.outputs.key }}
           restore-keys: |
             m2-
-      - uses: actions/setup-java@v6.0.1
+      - uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -114,7 +114,7 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-java@v6.0.1
+      - uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -149,10 +149,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-java@v6.0.1
+      - uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
+      - name: test1
+        run: echo "JAVA_HOME=$JAVA_HOME"
+      - name: test2
+        run: java -version
+      - name: test3
+        run: openssl s_client -connect code.jlab.org:443 -servername code.jlab.org </dev/null 2>/dev/null | openssl x509 -noout -issuer
+      - name: test4
+        run: keytool -list -cacerts -storepass changeit
       - uses: actions/cache/restore@v6
         with:
           path: ~/.m2/repository
@@ -190,7 +198,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -230,7 +238,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-java@v6.0.1
+      - uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ matrix.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -258,7 +266,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -281,7 +289,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -309,7 +317,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -366,7 +374,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -393,7 +401,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -417,7 +425,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -439,7 +447,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
@@ -479,7 +487,7 @@ jobs:
           path: pages/jacoco
       ### javadoc
       - name: set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.2.0
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.java_distribution }}
diff --git a/pom.xml b/pom.xml
index 866d948ee7..45dfd5fd61 100644
--- a/pom.xml
+++ b/pom.xml
@@ -11,6 +11,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <coat.deployment.url>file://myLocalMvnRepo</coat.deployment.url> <!-- must be consistent with 'deploy-coatjava.sh' -->
+    <blah>blah</blah>
   </properties>
 
   <modules>