diff --git a/.github/workflows/project_ci.yml b/.github/workflows/project_ci.yml
index de213c6905..a507b0899e 100644
--- a/.github/workflows/project_ci.yml
+++ b/.github/workflows/project_ci.yml
@@ -16,8 +16,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        jdk: [11, 17]
-        os: [ubuntu-20.04, windows-latest]
+        jdk: [17]
+        os: [ubuntu-latest, windows-latest]
     steps:
     - uses: actions/checkout@v4
       with:
@@ -54,7 +54,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        jdk: [11, 17]
+        jdk: [17]
         os: [ubuntu-20.04, windows-latest]
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/quickstart_ci.yml b/.github/workflows/quickstart_ci.yml
index f99012b488..83370f2a9c 100644
--- a/.github/workflows/quickstart_ci.yml
+++ b/.github/workflows/quickstart_ci.yml
@@ -30,7 +30,7 @@ on:
       MATRIX_JDK:
         description: 'the JDKs to be used on the test matrix, i.e. matrix.jdk'
         required: false
-        default: '"11", "17"'
+        default: '"17"'
         type: string
       MATRIX_OS:
         description: 'the OSes to be used on the test matrix, i.e. matrix.os'
diff --git a/.github/workflows/quickstart_ejb-txn-remote-call_ci.yml b/.github/workflows/quickstart_ejb-txn-remote-call_ci.yml
index 088cb3e202..647383eabf 100644
--- a/.github/workflows/quickstart_ejb-txn-remote-call_ci.yml
+++ b/.github/workflows/quickstart_ejb-txn-remote-call_ci.yml
@@ -17,7 +17,7 @@ env:
   TEST_PROVISIONED_SERVER: true
   TEST_BOOTABLE_JAR: false
   TEST_OPENSHIFT: true
-  MATRIX_JDK: '"11", "17"'
+  MATRIX_JDK: '"17"'
   MATRIX_OS: '"ubuntu-latest"'
   SERVER_PROVISIONING_SERVER_HOST: 'http://localhost'
   EXTRA_RUN_ARGS: '-DpostgresqlUsername="test" -DpostgresqlPassword="test"'
diff --git a/.github/workflows/quickstart_spring-resteasy_ci.yml b/.github/workflows/quickstart_spring-resteasy_ci.yml
index c5cb8e7d71..69d43fcdeb 100644
--- a/.github/workflows/quickstart_spring-resteasy_ci.yml
+++ b/.github/workflows/quickstart_spring-resteasy_ci.yml
@@ -12,4 +12,3 @@ jobs:
     with:
       QUICKSTART_PATH: spring-resteasy
       TEST_PROVISIONED_SERVER: true
-      MATRIX_JDK: '"17"'