diff --git a/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/EnumMapExample.java b/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/EnumMapExample.java
new file mode 100644
index 00000000..f845ef96
--- /dev/null
+++ b/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/EnumMapExample.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2023 VicTools.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.github.victools.jsonschema.examples;
+
+import com.fasterxml.classmate.ResolvedType;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.github.victools.jsonschema.generator.CustomDefinition;
+import com.github.victools.jsonschema.generator.CustomDefinitionProviderV2;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerationContext;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaKeyword;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+import com.github.victools.jsonschema.generator.TypeAttributeOverrideV2;
+import com.github.victools.jsonschema.generator.TypeContext;
+import com.github.victools.jsonschema.generator.TypeScope;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.Type;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Example created in response to #376.
+ *
+ * Representing a Map containing Enum values as keys.
+ */
+public class EnumMapExample implements SchemaGenerationExampleInterface {
+
+ @Override
+ public ObjectNode generateSchema() {
+ SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+ configBuilder.forTypesInGeneral()
+ .withCustomDefinitionProvider(new EnumMapDefinitionProvider(enumValue -> enumValue.name().toLowerCase()));
+ SchemaGeneratorConfig config = configBuilder.build();
+ SchemaGenerator generator = new SchemaGenerator(config);
+ return generator.generateSchema(Map.class, Job.class, JobDetails.class);
+ }
+
+ class EnumMapDefinitionProvider implements CustomDefinitionProviderV2 {
+
+ private Function, String> propertyNameSupplier;
+
+ EnumMapDefinitionProvider(Function, String> propertyNameSupplier) {
+ this.propertyNameSupplier = propertyNameSupplier;
+ }
+
+ @Override
+ public CustomDefinition provideCustomSchemaDefinition(ResolvedType targetType, SchemaGenerationContext context) {
+ ResolvedType keyType = context.getTypeContext().getTypeParameterFor(targetType, Map.class, 0);
+ if (keyType == null || !keyType.isInstanceOf(Enum.class)) {
+ // only consider Maps with an Enum as key
+ return null;
+ }
+ ResolvedType valueType = Optional.ofNullable(context.getTypeContext().getTypeParameterFor(targetType, Map.class, 1))
+ .orElseGet(() -> context.getTypeContext().resolve(Object.class));
+ ObjectNode customSchema = context.getGeneratorConfig().createObjectNode();
+ ObjectNode propertiesNode = context.getGeneratorConfig().createObjectNode();
+ customSchema.set(context.getKeyword(SchemaKeyword.TAG_PROPERTIES), propertiesNode);
+ Stream.of(((Class extends Enum>>) keyType.getErasedType()).getEnumConstants())
+ .map(this.propertyNameSupplier)
+ .forEach(propertyName -> propertiesNode.set(propertyName,
+ context.createStandardDefinitionReference(valueType, this)));
+ return new CustomDefinition(customSchema);
+ }
+ }
+
+ enum Job {
+ BLACKSMITH, FARMER;
+ }
+
+ static class JobDetails {
+ public Map trainingCosts;
+ }
+
+ enum TrainingResource {
+ WOOD, FOOD, STONE;
+ }
+}
diff --git a/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java b/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
index 2095bc07..2eb9c30d 100644
--- a/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
+++ b/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
@@ -32,6 +32,7 @@ public class ExampleTest {
@ParameterizedTest
@ValueSource(classes = {
AnnotationInheritanceExample.class,
+ EnumMapExample.class,
ExternalRefAnnotationExample.class,
ExternalRefPackageExample.class,
IfThenElseExample.class,
diff --git a/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/EnumMapExample-result.json b/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/EnumMapExample-result.json
new file mode 100644
index 00000000..61652def
--- /dev/null
+++ b/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/EnumMapExample-result.json
@@ -0,0 +1,31 @@
+{
+ "$schema" : "https://json-schema.org/draft/2020-12/schema",
+ "$defs" : {
+ "JobDetails" : {
+ "type" : "object",
+ "properties" : {
+ "trainingCosts" : {
+ "properties" : {
+ "wood" : {
+ "type" : "integer"
+ },
+ "food" : {
+ "type" : "integer"
+ },
+ "stone" : {
+ "type" : "integer"
+ }
+ }
+ }
+ }
+ }
+ },
+ "properties" : {
+ "blacksmith" : {
+ "$ref" : "#/$defs/JobDetails"
+ },
+ "farmer" : {
+ "$ref" : "#/$defs/JobDetails"
+ }
+ }
+}