diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 15d774245..5fcc99400 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -10,7 +10,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v3
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
       - name: Set maven settings.xml
         uses: whelk-io/maven-settings-xml-action@v21
diff --git a/.github/workflows/sonarcloud-branch.yml b/.github/workflows/sonarcloud-branch.yml
index b257a8101..ab5728a96 100644
--- a/.github/workflows/sonarcloud-branch.yml
+++ b/.github/workflows/sonarcloud-branch.yml
@@ -28,7 +28,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
-          java-version: 17
+          java-version: 21
 
       - name: Cache SonarCloud packages
         uses: actions/cache@v3
diff --git a/.github/workflows/sonarcloud-pr.yml b/.github/workflows/sonarcloud-pr.yml
index a4274b34f..dd5293a0d 100644
--- a/.github/workflows/sonarcloud-pr.yml
+++ b/.github/workflows/sonarcloud-pr.yml
@@ -51,7 +51,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
-          java-version: 17
+          java-version: 21
 
       - name: Cache SonarCloud packages
         uses: actions/cache@v3
diff --git a/README.md b/README.md
index 38f581b8c..2a124620a 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ In the following, a list of all supported languages with their supported languag
 
 | Language                                                   |                                                                                Version | CLI Argument Name | [state](https://github.com/jplag/JPlag/wiki/2.-Supported-Languages) |  parser   |
 |------------------------------------------------------------|---------------------------------------------------------------------------------------:|-------------------|:-------------------------------------------------------------------:|:---------:|
-| [Java](https://www.java.com)                               |                                                                                     17 | java              |                               mature                                |   JavaC   |
+| [Java](https://www.java.com)                               |                                                                                     21 | java              |                               mature                                |   JavaC   |
 | [C/C++](https://isocpp.org)                                |                                                                                     11 | cpp               |                               legacy                                |  JavaCC   |
 | [C/C++](https://isocpp.org)                                |                                                                                     14 | cpp2              |                                beta                                 |  ANTLR 4  |
 | [C#](https://docs.microsoft.com/en-us/dotnet/csharp/)      |                                                                                      6 | csharp            |                                beta                                 |  ANTLR 4  |
@@ -40,7 +40,7 @@ In the following, a list of all supported languages with their supported languag
 | Text (naive)                                               |                                                                                      - | text              |                               legacy                                |  CoreNLP  |
 
 ## Download and Installation
-You need Java SE 17 to run or build JPlag.
+You need Java SE 21 to run or build JPlag.
 
 ### Downloading a release
 * Download a [released version](https://github.com/jplag/jplag/releases).
diff --git a/languages/cpp/pom.xml b/languages/cpp/pom.xml
index 54529df6b..734f52d92 100644
--- a/languages/cpp/pom.xml
+++ b/languages/cpp/pom.xml
@@ -21,7 +21,7 @@
                         </goals>
                         <phase>generate-sources</phase>
                         <configuration>
-                            <jdkVersion>17</jdkVersion>
+                            <jdkVersion>21</jdkVersion>
                             <javadocFriendlyComments>true</javadocFriendlyComments>
                             <packageName>de.jplag.cpp</packageName>
                             <sourceDirectory>src/main/javacc</sourceDirectory>