diff --git a/gradle.properties b/gradle.properties
index 3e1d21f..c117d98 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,12 +1,12 @@
 group = org.xbib
 name = marc
-version = 2.3.0
+version = 2.3.1
 
 gradle.wrapper.version = 6.4.1
-xbib-content.version = 2.2.0
-xbib-bibliographic-character-sets.version = 1.0.0
+xbib-content.version = 2.3.1
+xbib-bibliographic-character-sets.version = 2.0.0
 xalan.version = 2.7.2
 xmlunit-matchers.version = 2.6.3
 system-rules.version = 1.19.0
-mockito.version = 3.1.0
+mockito.version = 3.3.3
 marc4j.version = 2.9.1
diff --git a/gradle/compile/java.gradle b/gradle/compile/java.gradle
index 7b1e601..9c8798d 100644
--- a/gradle/compile/java.gradle
+++ b/gradle/compile/java.gradle
@@ -33,3 +33,11 @@ task javadocJar(type: Jar, dependsOn: javadoc) {
 artifacts {
     archives sourcesJar, javadocJar
 }
+
+tasks.withType(JavaCompile) {
+    options.compilerArgs << '-Xlint:all'
+}
+
+javadoc {
+    options.addStringOption('Xdoclint:none', '-quiet')
+}
diff --git a/gradle/codequality/todo.gradle b/gradle/quality/todo.gradle
similarity index 100%
rename from gradle/codequality/todo.gradle
rename to gradle/quality/todo.gradle
diff --git a/src/main/java/module-info.java b/src/main/java/module-info.java
index 1469045..74c4b8b 100644
--- a/src/main/java/module-info.java
+++ b/src/main/java/module-info.java
@@ -15,6 +15,6 @@ module org.xbib.marc {
     exports org.xbib.marc.transformer.field;
     exports org.xbib.marc.transformer.value;
     exports org.xbib.marc.xml;
+    requires transitive java.xml;
     requires java.logging;
-    requires java.xml;
 }
diff --git a/src/main/java/org/xbib/marc/io/StreamTokenHandler.java b/src/main/java/org/xbib/marc/io/StreamTokenHandler.java
index ae841c0..a6d7184 100644
--- a/src/main/java/org/xbib/marc/io/StreamTokenHandler.java
+++ b/src/main/java/org/xbib/marc/io/StreamTokenHandler.java
@@ -23,7 +23,7 @@ import java.io.InputStream;
  * Interface for stream token handlers.
  */
 @FunctionalInterface
-interface StreamTokenHandler {
+public interface StreamTokenHandler {
     /**
      * Process token.
      * @param token the token
diff --git a/src/main/java/org/xbib/marc/json/JsonObject.java b/src/main/java/org/xbib/marc/json/JsonObject.java
index ca3d6b9..2efc7c2 100755
--- a/src/main/java/org/xbib/marc/json/JsonObject.java
+++ b/src/main/java/org/xbib/marc/json/JsonObject.java
@@ -57,7 +57,7 @@ import java.util.Objects;
  * may lead to an inconsistent state.
  * </p>
  */
-class JsonObject extends JsonValue implements Iterable<JsonObject.Member> {
+public class JsonObject extends JsonValue implements Iterable<JsonObject.Member> {
 
     private final List<String> names;
 
@@ -68,7 +68,7 @@ class JsonObject extends JsonValue implements Iterable<JsonObject.Member> {
     /**
      * Creates a new empty JsonObject.
      */
-    JsonObject() {
+    public JsonObject() {
         names = new ArrayList<>();
         values = new ArrayList<>();
         table = new HashIndexTable();
@@ -674,12 +674,12 @@ class JsonObject extends JsonValue implements Iterable<JsonObject.Member> {
     /**
      * Represents a member of a JSON object, a pair of a name and a value.
      */
-    static class Member {
+    public static class Member {
 
         private final String name;
         private final JsonValue value;
 
-        Member(String name, JsonValue value) {
+        public Member(String name, JsonValue value) {
             this.name = name;
             this.value = value;
         }
diff --git a/src/main/java/org/xbib/marc/json/JsonValue.java b/src/main/java/org/xbib/marc/json/JsonValue.java
index bcca77b..90a6a18 100755
--- a/src/main/java/org/xbib/marc/json/JsonValue.java
+++ b/src/main/java/org/xbib/marc/json/JsonValue.java
@@ -49,11 +49,7 @@ import java.io.StringWriter;
  * appropriate target type.
  * </p>
  */
-abstract class JsonValue {
-
-    JsonValue() {
-        // prevent subclasses outside of this package
-    }
+public abstract class JsonValue {
 
     /**
      * Detects whether this value represents a JSON object. If this is the case, this value is an
diff --git a/src/main/java/org/xbib/marc/json/JsonWriterConfig.java b/src/main/java/org/xbib/marc/json/JsonWriterConfig.java
index cef9f5c..48fa513 100755
--- a/src/main/java/org/xbib/marc/json/JsonWriterConfig.java
+++ b/src/main/java/org/xbib/marc/json/JsonWriterConfig.java
@@ -24,7 +24,7 @@ import java.util.Arrays;
  * Controls the formatting of the JSON output. Use one of the available constants.
  */
 @FunctionalInterface
-interface JsonWriterConfig {
+public interface JsonWriterConfig {
 
     JsonWriter createWriter(Writer writer);