diff --git a/src/main/java/it/cavallium/data/generator/CustomTypesConfiguration.java b/src/main/java/it/cavallium/data/generator/CustomTypesConfiguration.java
index 7e66812..ef9bbe0 100644
--- a/src/main/java/it/cavallium/data/generator/CustomTypesConfiguration.java
+++ b/src/main/java/it/cavallium/data/generator/CustomTypesConfiguration.java
@@ -1,7 +1,32 @@
 package it.cavallium.data.generator;
 
+import com.squareup.javapoet.ClassName;
+import com.squareup.javapoet.ParameterizedTypeName;
+import com.squareup.javapoet.TypeName;
+
 public class CustomTypesConfiguration {
 
-	public String javaClass;
+	private String javaClass;
 	public String serializer;
+
+	public void setJavaClass(String javaClass) {
+		this.javaClass = javaClass;
+	}
+
+	public TypeName getJavaClassType() {
+		int indexOfGeneric;
+		if ((indexOfGeneric = javaClass.indexOf("<")) == -1) {
+			return ClassName.bestGuess(javaClass);
+		} else {
+			var rawTypesArray = javaClass.substring(indexOfGeneric + 1, javaClass.length() - 1).split(",");
+			var genericsResult = new TypeName[rawTypesArray.length];
+			int i = 0;
+			for (String rawType : rawTypesArray) {
+				genericsResult[i] = ClassName.bestGuess(rawType);
+				i++;
+			}
+			var base = ClassName.bestGuess(javaClass.substring(0, indexOfGeneric));
+			return ParameterizedTypeName.get(base, genericsResult);
+		}
+	}
 }
diff --git a/src/main/java/it/cavallium/data/generator/SourcesGenerator.java b/src/main/java/it/cavallium/data/generator/SourcesGenerator.java
index 554d9b7..cb51f0c 100644
--- a/src/main/java/it/cavallium/data/generator/SourcesGenerator.java
+++ b/src/main/java/it/cavallium/data/generator/SourcesGenerator.java
@@ -724,14 +724,14 @@ public class SourcesGenerator {
 									.build()
 					);
 					typeMustGenerateSerializer.put(key, false);
-					typeTypes.put(key, ClassName.bestGuess(customTypeConfiguration.javaClass));
+					typeTypes.put(key, customTypeConfiguration.getJavaClassType());
 					typeFamily.put(key, Family.OTHER);
 					if (nextVersionCustomTypeConfiguration.isPresent()) {
-						nextVersionTypeTypes.put(key, ClassName.bestGuess(nextVersionCustomTypeConfiguration.get().javaClass));
+						nextVersionTypeTypes.put(key, nextVersionCustomTypeConfiguration.get().getJavaClassType());
 						nextVersionTypeFamily.put(key, Family.OTHER);
 					}
 
-					var arrayClassName = ClassName.bestGuess(customTypeConfiguration.javaClass);
+					var arrayClassName = customTypeConfiguration.getJavaClassType();
 					var neededTypes = registerNeededTypes(versionConfiguration,
 							Family.OTHER,
 							key,
@@ -2581,8 +2581,8 @@ public class SourcesGenerator {
 			HashMap<String, Family> typeFamily,
 			@Nullable HashMap<String, TypeName> nextVersionTypeTypes,
 			@Nullable HashMap<String, Family> nextVersionTypeFamily,
-			Supplier<ClassName> arrayClassName,
-			Supplier<ClassName> nextArrayClassName) {
+			Supplier<TypeName> arrayClassName,
+			Supplier<TypeName> nextArrayClassName) {
 		// Check if the nullable type is needed
 		boolean nullableTypeNeeded = versionConfiguration.classes
 				.values()