diff --git a/.github/workflows/nightly-artifacts.yml b/.github/workflows/nightly-artifacts.yml
index 4809147..5daba82 100644
--- a/.github/workflows/nightly-artifacts.yml
+++ b/.github/workflows/nightly-artifacts.yml
@@ -63,6 +63,8 @@ jobs:
         shell: pwsh
         run: |
           New-Item -ItemType Directory -Force -Path dist | Out-Null
+          $addModules = & java packaging/AddModules.java
+          if ($LASTEXITCODE -ne 0) { throw "Failed to resolve --add-modules from module-info.java" }
           jpackage `
             --type app-image `
             --name praktiKST `
@@ -71,7 +73,7 @@ jobs:
             --main-jar app.jar `
             --main-class kst4contest.view.Kst4ContestApplication `
             --module-path target/dist-libs `
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net `
+            --add-modules $addModules `
             --dest dist
 
       - name: Create Windows ZIP
@@ -120,6 +122,7 @@ jobs:
       - name: Build app-image with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -128,7 +131,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
       - name: Create AppDir metadata
@@ -206,6 +209,7 @@ jobs:
       - name: Build Debian package
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type deb \
             --name KST4Contest \
@@ -214,7 +218,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --linux-package-deps "libgstreamer1.0-0,libgstreamer-plugins-base1.0-0,gstreamer1.0-plugins-good" \
             --dest dist
           DEB="$(ls dist/*.deb | head -n 1)"
@@ -266,6 +270,7 @@ jobs:
       - name: Build Fedora package
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type rpm \
             --name KST4Contest \
@@ -274,7 +279,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --linux-package-deps "gstreamer1,gstreamer1-plugins-base,gstreamer1-plugins-good" \
             --dest dist
           RPM="$(ls dist/*.rpm | head -n 1)"
@@ -328,6 +333,7 @@ jobs:
       - name: Build app-image with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -336,7 +342,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
       - name: Build Arch Linux package artifact
@@ -447,6 +453,7 @@ jobs:
           ./mvnw -B -DskipTests package dependency:copy-dependencies -DincludeScope=runtime -DoutputDirectory=target/dist-libs
           cp "$(ls -t target/praktiKST-*.jar | head -n 1)" target/dist-libs/app.jar
           mkdir -p target/flatpak-src
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -455,7 +462,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest target/flatpak-src
 
       - name: Create Flatpak manifest
@@ -635,6 +642,7 @@ jobs:
       - name: Build macOS DMG with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type dmg \
             --name KST4Contest \
@@ -643,7 +651,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
         env:
diff --git a/.github/workflows/pr-compile-check.yml b/.github/workflows/pr-compile-check.yml
index 9a11928..fd3228d 100644
--- a/.github/workflows/pr-compile-check.yml
+++ b/.github/workflows/pr-compile-check.yml
@@ -27,5 +27,8 @@ jobs:
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
 
+      - name: Verify packaging module list matches module-info.java
+        run: java packaging/AddModules.java --verify-pom
+
       - name: Compile
         run: ./mvnw -B -DskipTests compile
diff --git a/.github/workflows/tagged-release.yml b/.github/workflows/tagged-release.yml
index 5e0b82e..56e3a4c 100644
--- a/.github/workflows/tagged-release.yml
+++ b/.github/workflows/tagged-release.yml
@@ -48,6 +48,8 @@ jobs:
         shell: pwsh
         run: |
           New-Item -ItemType Directory -Force -Path dist | Out-Null
+          $addModules = & java packaging/AddModules.java
+          if ($LASTEXITCODE -ne 0) { throw "Failed to resolve --add-modules from module-info.java" }
           jpackage `
             --type app-image `
             --name praktiKST `
@@ -56,7 +58,7 @@ jobs:
             --main-jar app.jar `
             --main-class kst4contest.view.Kst4ContestApplication `
             --module-path target/dist-libs `
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net `
+            --add-modules $addModules `
             --dest dist
 
       - name: Create Windows ZIP
@@ -98,6 +100,7 @@ jobs:
       - name: Build app-image with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -106,7 +109,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
       - name: Create AppDir metadata
@@ -177,6 +180,7 @@ jobs:
       - name: Build Debian package
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type deb \
             --name KST4Contest \
@@ -185,7 +189,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --linux-package-deps "libgstreamer1.0-0,libgstreamer-plugins-base1.0-0,gstreamer1.0-plugins-good" \
             --dest dist
           DEB="$(ls dist/*.deb | head -n 1)"
@@ -230,6 +234,7 @@ jobs:
       - name: Build Fedora package
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type rpm \
             --name KST4Contest \
@@ -238,7 +243,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --linux-package-deps "gstreamer1,gstreamer1-plugins-base,gstreamer1-plugins-good" \
             --dest dist
           RPM="$(ls dist/*.rpm | head -n 1)"
@@ -283,6 +288,7 @@ jobs:
       - name: Build app-image with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -291,7 +297,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
       - name: Build Arch Linux package artifact
@@ -393,6 +399,7 @@ jobs:
           ./mvnw -B -DskipTests package dependency:copy-dependencies -DincludeScope=runtime -DoutputDirectory=target/dist-libs
           cp "$(ls -t target/praktiKST-*.jar | head -n 1)" target/dist-libs/app.jar
           mkdir -p target/flatpak-src
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type app-image \
             --name KST4Contest \
@@ -401,7 +408,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest target/flatpak-src
 
       - name: Create Flatpak manifest
@@ -523,6 +530,7 @@ jobs:
       - name: Build macOS DMG with jpackage
         run: |
           mkdir -p dist
+          ADD_MODULES="$(java packaging/AddModules.java)"
           jpackage \
             --type dmg \
             --name KST4Contest \
@@ -531,7 +539,7 @@ jobs:
             --main-jar app.jar \
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
-            --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+            --add-modules "$ADD_MODULES" \
             --dest dist
 
         env:
diff --git a/packaging/AddModules.java b/packaging/AddModules.java
new file mode 100644
index 0000000..e3d8f2b
--- /dev/null
+++ b/packaging/AddModules.java
@@ -0,0 +1,128 @@
+/*
+ * Derives the jpackage --add-modules list from module-info.java so that the
+ * packaging scripts never drift from the module descriptor again.
+ *
+ * Run as a single file source program, which behaves identically on the Linux,
+ * macOS and Windows runners:
+ *
+ *     java packaging/AddModules.java                 print the module list
+ *     java packaging/AddModules.java --verify-pom    fail if pom.xml drifted
+ *
+ * Only platform modules are emitted. Third party requires such as jlayer are
+ * skipped because they are supplied as ordinary jars on the class path, and
+ * automatic modules cannot be linked into a runtime image at all. Test only
+ * requires such as org.junit.jupiter.api are skipped for the same reason.
+ */
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public final class AddModules {
+
+    private static final Path DESCRIPTOR =
+            Path.of("src", "main", "java", "module-info.java");
+
+    private static final Path POM = Path.of("pom.xml");
+
+    /** Matches "requires [transitive] [static] some.module;" in any order. */
+    private static final Pattern REQUIRES = Pattern.compile(
+            "requires\\s+((?:transitive\\s+|static\\s+)*)([A-Za-z0-9_.]+)\\s*;");
+
+    private static final Pattern ADD_MODULE =
+            Pattern.compile("<addmodule>\\s*([A-Za-z0-9_.]+)\\s*</addmodule>");
+
+    private static final Pattern BLOCK_COMMENT =
+            Pattern.compile("/\\*.*?\\*/", Pattern.DOTALL);
+
+    private static final Pattern LINE_COMMENT = Pattern.compile("//[^\\n]*");
+
+    private AddModules() {
+    }
+
+    public static void main(String[] args) throws IOException {
+        boolean verifyPom = args.length > 0 && "--verify-pom".equals(args[0]);
+
+        Set<String> required = platformModules(read(DESCRIPTOR));
+        if (required.isEmpty()) {
+            fail("No platform modules found in " + DESCRIPTOR);
+        }
+
+        if (!verifyPom) {
+            System.out.println(String.join(",", required));
+            return;
+        }
+
+        Set<String> declared = new TreeSet<>();
+        Matcher matcher = ADD_MODULE.matcher(read(POM));
+        while (matcher.find()) {
+            declared.add(matcher.group(1));
+        }
+
+        if (declared.equals(required)) {
+            System.out.println("pom.xml <addmodules> matches module-info.java ("
+                    + required.size() + " modules)");
+            return;
+        }
+
+        Set<String> missing = new TreeSet<>(required);
+        missing.removeAll(declared);
+        Set<String> extra = new TreeSet<>(declared);
+        extra.removeAll(required);
+
+        System.err.println("pom.xml <addmodules> drifted from module-info.java.");
+        if (!missing.isEmpty()) {
+            System.err.println("  missing in pom.xml: " + String.join(", ", missing));
+        }
+        if (!extra.isEmpty()) {
+            System.err.println("  not required by module-info.java: "
+                    + String.join(", ", extra));
+        }
+        System.err.println("  expected: " + String.join(",", required));
+        System.exit(1);
+    }
+
+    /** Returns the platform modules required by the given descriptor, sorted. */
+    static Set<String> platformModules(String source) {
+        String stripped = LINE_COMMENT.matcher(
+                BLOCK_COMMENT.matcher(source).replaceAll(" ")).replaceAll(" ");
+
+        Set<String> modules = new TreeSet<>();
+        Matcher matcher = REQUIRES.matcher(stripped);
+        while (matcher.find()) {
+            // "requires static" is a compile time only dependency and must not
+            // be linked into the shipped runtime image.
+            if (matcher.group(1).contains("static")) {
+                continue;
+            }
+            String module = matcher.group(2);
+            if (isPlatformModule(module)) {
+                modules.add(module);
+            }
+        }
+        return modules;
+    }
+
+    private static boolean isPlatformModule(String module) {
+        return module.startsWith("java.")
+                || module.startsWith("jdk.")
+                || module.startsWith("javafx.");
+    }
+
+    private static String read(Path path) throws IOException {
+        if (!Files.isRegularFile(path)) {
+            fail("Not found: " + path.toAbsolutePath()
+                    + " (run this from the repository root)");
+        }
+        return Files.readString(path);
+    }
+
+    private static void fail(String message) {
+        System.err.println(message);
+        System.exit(2);
+    }
+}
diff --git a/packaging/aur/kst4contest-git/PKGBUILD b/packaging/aur/kst4contest-git/PKGBUILD
index ca3fb74..4452949 100644
--- a/packaging/aur/kst4contest-git/PKGBUILD
+++ b/packaging/aur/kst4contest-git/PKGBUILD
@@ -33,6 +33,7 @@ build() {
     cp "$(ls -t target/praktiKST-*.jar | head -n 1)" target/dist-libs/app.jar
 
     mkdir -p dist
+    ADD_MODULES="$(java packaging/AddModules.java)"
     jpackage \
         --type app-image \
         --name KST4Contest \
@@ -40,7 +41,7 @@ build() {
         --main-jar app.jar \
         --main-class kst4contest.view.Kst4ContestApplication \
         --module-path target/dist-libs \
-        --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+        --add-modules "$ADD_MODULES" \
         --dest dist
 }
 
diff --git a/packaging/aur/kst4contest/PKGBUILD b/packaging/aur/kst4contest/PKGBUILD
index 467b08b..7ce00d8 100644
--- a/packaging/aur/kst4contest/PKGBUILD
+++ b/packaging/aur/kst4contest/PKGBUILD
@@ -26,6 +26,14 @@ build() {
     cp "$(ls -t target/praktiKST-*.jar | head -n 1)" target/dist-libs/app.jar
 
     mkdir -p dist
+    # This PKGBUILD builds from a released source tarball, which may predate
+    # packaging/AddModules.java. Older tarballs carry the same list in pom.xml,
+    # which the build keeps in sync with module-info.java from v1.42.0 onwards.
+    if [ -f packaging/AddModules.java ]; then
+        ADD_MODULES="$(java packaging/AddModules.java)"
+    else
+        ADD_MODULES="$(sed -n 's:.*<addmodule>\(.*\)</addmodule>.*:\1:p' pom.xml | paste -sd,)"
+    fi
     jpackage \
         --type app-image \
         --name KST4Contest \
@@ -33,7 +41,7 @@ build() {
         --main-jar app.jar \
         --main-class kst4contest.view.Kst4ContestApplication \
         --module-path target/dist-libs \
-        --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec,jdk.net \
+        --add-modules "$ADD_MODULES" \
         --dest dist
 }
 
diff --git a/pom.xml b/pom.xml
index a167eb8..eca17aa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -56,6 +56,7 @@
         <javafx.maven.plugin>0.0.8</javafx.maven.plugin>
         <spotbugs.maven.plugin>4.9.8.2</spotbugs.maven.plugin>
         <spotbugs.version>4.9.8</spotbugs.version>
+        <exec.maven.plugin>3.1.0</exec.maven.plugin>
 
         <!-- other properties -->
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -208,6 +209,36 @@
                 </executions>
             </plugin>
 
+            <!--
+                Fails the build whenever the jpackage module list below drifts
+                from the requires clauses in src/main/java/module-info.java.
+                This is bound to validate rather than to a workflow trigger so
+                it also fires on direct pushes to main, on local builds and in
+                the AUR PKGBUILDs, which never run the pull request check.
+            -->
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <version>${exec.maven.plugin}</version>
+                <executions>
+                    <execution>
+                        <id>verify-packaging-module-list</id>
+                        <phase>validate</phase>
+                        <goals>
+                            <goal>exec</goal>
+                        </goals>
+                        <configuration>
+                            <executable>${java.home}/bin/java</executable>
+                            <workingDirectory>${project.basedir}</workingDirectory>
+                            <arguments>
+                                <argument>packaging/AddModules.java</argument>
+                                <argument>--verify-pom</argument>
+                            </arguments>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
@@ -436,16 +467,26 @@
                                     </dependencyset>
                                 </dependencysets>
                             </modulepath>
+                            <!--
+                                Keep in sync with the requires clauses in
+                                src/main/java/module-info.java. The packaging
+                                scripts derive this list automatically via
+                                packaging/AddModules.java, and the PR check
+                                runs that helper in its pom verification mode
+                                so this block cannot drift unnoticed.
+                            -->
                             <addmodules>
-                                <addmodule>javafx.controls</addmodule>
-                                <addmodule>javafx.graphics</addmodule>
-                                <addmodule>javafx.fxml</addmodule>
-                                <addmodule>javafx.web</addmodule>
-                                <addmodule>javafx.media</addmodule>
-                                <addmodule>java.sql</addmodule>
+                                <addmodule>java.desktop</addmodule>
                                 <addmodule>java.net.http</addmodule>
+                                <addmodule>java.sql</addmodule>
+                                <addmodule>javafx.controls</addmodule>
+                                <addmodule>javafx.fxml</addmodule>
+                                <addmodule>javafx.media</addmodule>
+                                <addmodule>javafx.web</addmodule>
                                 <addmodule>jdk.crypto.ec</addmodule>
+                                <addmodule>jdk.jsobject</addmodule>
                                 <addmodule>jdk.net</addmodule>
+                                <addmodule>jdk.xml.dom</addmodule>
                             </addmodules>
                             <mainclass>${main.class}</mainclass>
                             <input>${project.build.directory}/modules</input>