diff --git a/build/docker/ubuntu-focal/Dockerfile b/build/docker/ubuntu-focal/Dockerfile
index b356245..115c2a5 100644
--- a/build/docker/ubuntu-focal/Dockerfile
+++ b/build/docker/ubuntu-focal/Dockerfile
@@ -168,7 +168,7 @@
       ant \
       ant-optional \
       maven \
-      openjdk-17-jdk-headless && \
+      openjdk-11-jdk-headless && \
       `# Gradle` \
       wget https://services.gradle.org/distributions/gradle-$GRADLE_VERSION-bin.zip -q -O /tmp/gradle-$GRADLE_VERSION-bin.zip && \
       (echo "f6b8596b10cce501591e92f229816aa4046424f3b24d771751b06779d58c8ec4  /tmp/gradle-$GRADLE_VERSION-bin.zip" | sha256sum -c -) && \
diff --git a/lib/java/gradle/sourceConfiguration.gradle b/lib/java/gradle/sourceConfiguration.gradle
index 044a114..47f4ff0 100644
--- a/lib/java/gradle/sourceConfiguration.gradle
+++ b/lib/java/gradle/sourceConfiguration.gradle
@@ -53,6 +53,13 @@
     ]
 }
 
+tasks.withType(Javadoc) {
+    failOnError false
+    options.addStringOption('Xdoclint:none', '-quiet')
+    options.addStringOption('encoding', 'UTF-8')
+    options.addStringOption('charSet', 'UTF-8')
+}
+
 // ----------------------------------------------------------------------------
 // Jar packaging details
 processResources {