diff --git a/tooling/metamodel-generator/src/main/java/org/hibernate/processor/HibernateProcessor.java b/tooling/metamodel-generator/src/main/java/org/hibernate/processor/HibernateProcessor.java
index 57770f1c31..1dd4c9cf75 100644
--- a/tooling/metamodel-generator/src/main/java/org/hibernate/processor/HibernateProcessor.java
+++ b/tooling/metamodel-generator/src/main/java/org/hibernate/processor/HibernateProcessor.java
@@ -291,7 +291,7 @@ public class HibernateProcessor extends AbstractProcessor {
 		context.setInclude( options.getOrDefault( INCLUDE, "*" ) );
 		context.setExclude( options.getOrDefault( EXCLUDE, "" ) );
 
-		context.setIndexing( parseBoolean( options.get( INDEX ) ) );
+		context.setIndexing( parseBoolean( options.getOrDefault( INDEX, "true" ) ) );
 
 		return parseBoolean( options.get( FULLY_ANNOTATION_CONFIGURED_OPTION ) );
 	}
diff --git a/tooling/metamodel-generator/src/main/java/org/hibernate/processor/validation/ProcessorSessionFactory.java b/tooling/metamodel-generator/src/main/java/org/hibernate/processor/validation/ProcessorSessionFactory.java
index 2b9afc1c5e..381b1ba924 100644
--- a/tooling/metamodel-generator/src/main/java/org/hibernate/processor/validation/ProcessorSessionFactory.java
+++ b/tooling/metamodel-generator/src/main/java/org/hibernate/processor/validation/ProcessorSessionFactory.java
@@ -134,7 +134,6 @@ public abstract class ProcessorSessionFactory extends MockSessionFactory {
 		}
 	}
 
-
 	@Override
 	Type propertyType(String typeName, String propertyPath) {
 		final TypeElement type = findClassByQualifiedName(typeName);
@@ -226,8 +225,10 @@ public abstract class ProcessorSessionFactory extends MockSessionFactory {
 		}
 		if ( indexing ) {
 			final Set<String> indexed = getIndexedEnumTypesByValue(value);
-			enumTypesByValue.put(value, indexed);
-			return indexed;
+			if ( indexed != null ) {
+				enumTypesByValue.put(value, indexed);
+				return indexed;
+			}
 		}
 		//TODO: else do a full scan like in findEntityByUnqualifiedName()
 		return null;