diff --git a/.github/workflows/pr-test.yml b/.github/workflows/pr-test.yml
index 0eb52772..1103260d 100644
--- a/.github/workflows/pr-test.yml
+++ b/.github/workflows/pr-test.yml
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        jdk: [17]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -71,7 +71,7 @@ jobs:
     if: needs.find_changes.outputs.core == 'true'
     strategy:
       matrix:
-        jdk: [17]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -99,7 +99,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -130,7 +130,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -157,7 +157,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true' || needs.find_changes.outputs.backend == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -188,7 +188,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true' || needs.find_changes.outputs.backend == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1ba68f2e..7b1a188d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        jdk: [17]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -65,7 +65,7 @@ jobs:
     if: needs.find_changes.outputs.core == 'true'
     strategy:
       matrix:
-        jdk: [17]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -93,7 +93,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -121,7 +121,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -148,7 +148,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true' || needs.find_changes.outputs.backend == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
@@ -176,7 +176,7 @@ jobs:
     if: needs.find_changes.outputs.store == 'true' || needs.find_changes.outputs.backend == 'true'
     strategy:
       matrix:
-        jdk: [ 17 ]
+        jdk: [17, 21]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK
diff --git a/pom.xml b/pom.xml
index e4845c97..b882f9fe 100644
--- a/pom.xml
+++ b/pom.xml
@@ -9,7 +9,7 @@
 
     <groupId>com.the-qa-company</groupId>
     <artifactId>qendpoint-parent</artifactId>
-    <version>2.3.0</version>
+    <version>2.4.0</version>
 
     <packaging>pom</packaging>
 
diff --git a/qendpoint-backend/pom.xml b/qendpoint-backend/pom.xml
index 2723e311..47ee658e 100644
--- a/qendpoint-backend/pom.xml
+++ b/qendpoint-backend/pom.xml
@@ -4,7 +4,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>qendpoint-backend</artifactId>
-    <version>2.3.0</version>
+    <version>2.4.0</version>
 
     <packaging>jar</packaging>
 
@@ -15,7 +15,7 @@
     <parent>
         <groupId>com.the-qa-company</groupId>
         <artifactId>qendpoint-parent</artifactId>
-        <version>2.3.0</version>
+        <version>2.4.0</version>
     </parent>
 
     <licenses>
diff --git a/qendpoint-cli/pom.xml b/qendpoint-cli/pom.xml
index ce9067db..4b4db3bf 100644
--- a/qendpoint-cli/pom.xml
+++ b/qendpoint-cli/pom.xml
@@ -2,7 +2,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>qendpoint-cli</artifactId>
-    <version>2.3.0</version>
+    <version>2.4.0</version>
 
     <name>qendpoint package</name>
     <description>Package of the qendpoint.</description>
@@ -11,7 +11,7 @@
     <parent>
         <groupId>com.the-qa-company</groupId>
         <artifactId>qendpoint-parent</artifactId>
-        <version>2.3.0</version>
+        <version>2.4.0</version>
     </parent>
 
     <dependencies>
diff --git a/qendpoint-core/pom.xml b/qendpoint-core/pom.xml
index 5a8cac4a..1a83748d 100644
--- a/qendpoint-core/pom.xml
+++ b/qendpoint-core/pom.xml
@@ -4,7 +4,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>qendpoint-core</artifactId>
-    <version>2.3.0</version>
+    <version>2.4.0</version>
 
     <packaging>jar</packaging>
 
@@ -27,7 +27,7 @@
     <parent>
         <groupId>com.the-qa-company</groupId>
         <artifactId>qendpoint-parent</artifactId>
-        <version>2.3.0</version>
+        <version>2.4.0</version>
     </parent>
 
     <licenses>
diff --git a/qendpoint-store/pom.xml b/qendpoint-store/pom.xml
index 62bcdf64..b6460430 100644
--- a/qendpoint-store/pom.xml
+++ b/qendpoint-store/pom.xml
@@ -3,7 +3,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>qendpoint</artifactId>
-    <version>2.3.0</version>
+    <version>2.4.0</version>
 
     <packaging>jar</packaging>
 
@@ -13,7 +13,7 @@
     <parent>
         <groupId>com.the-qa-company</groupId>
         <artifactId>qendpoint-parent</artifactId>
-        <version>2.3.0</version>
+        <version>2.4.0</version>
     </parent>
 
     <licenses>
diff --git a/release/RELEASE.md b/release/RELEASE.md
index 99c7593a..f935d2a0 100644
--- a/release/RELEASE.md
+++ b/release/RELEASE.md
@@ -1,3 +1,4 @@
-- cache constants in query optimiser (#527)
-- update spring to 3.4.0 (#518)
-- remove rdf4j solr from the backend dependencies (#518)
+- show lucene indexes names when loading (#537)
+- send HTTP 400 with bad query (#384)
+- update commons-compress to 1.26.0 and remove protobuf from mvn (#549)
+- cache superblock locations (#528)
diff --git a/release/RELEASE.md_old b/release/RELEASE.md_old
index 73155377..16cebe66 100644
--- a/release/RELEASE.md_old
+++ b/release/RELEASE.md_old
@@ -1,3 +1,8 @@
+## Version 2.3.0
+        
+- cache constants in query optimiser (#527)
+- update spring to 3.4.0 (#518)
+- remove rdf4j solr from the backend dependencies (#518)
 ## Version 2.2.0
         
 - update rdf4j to 5.1.0