diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/ArrayBinder.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/ArrayBinder.java
index 70dac910326..ff4299dc03e 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/ArrayBinder.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/ArrayBinder.java
@@ -38,12 +38,12 @@ class ArrayBinder extends IndexedElementsBinder<Object> {
 	@Override
 	protected Object bindAggregate(ConfigurationPropertyName name, Bindable<?> target,
 			AggregateElementBinder elementBinder) {
-		IndexedCollectionSupplier collection = new IndexedCollectionSupplier(
-				ArrayList::new);
+		IndexedCollectionSupplier result = new IndexedCollectionSupplier(ArrayList::new);
+		ResolvableType aggregateType = target.getType();
 		ResolvableType elementType = target.getType().getComponentType();
-		bindIndexed(name, elementBinder, collection, target.getType(), elementType);
-		if (collection.wasSupplied()) {
-			List<Object> list = (List<Object>) collection.get();
+		bindIndexed(name, elementBinder, aggregateType, elementType, result);
+		if (result.wasSupplied()) {
+			List<Object> list = (List<Object>) result.get();
 			Object array = Array.newInstance(elementType.resolve(), list.size());
 			for (int i = 0; i < list.size(); i++) {
 				Array.set(array, i, list.get(i));
diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
index dd52f16201b..8a14562a61e 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
@@ -40,14 +40,14 @@ class CollectionBinder extends IndexedElementsBinder<Collection<Object>> {
 			AggregateElementBinder elementBinder) {
 		Class<?> collectionType = (target.getValue() == null ? target.getType().resolve()
 				: List.class);
-		IndexedCollectionSupplier collection = new IndexedCollectionSupplier(
-				() -> CollectionFactory.createCollection(collectionType, 0));
-		ResolvableType elementType = target.getType().asCollection().getGeneric();
 		ResolvableType aggregateType = ResolvableType.forClassWithGenerics(List.class,
 				target.getType().asCollection().getGenerics());
-		bindIndexed(name, elementBinder, collection, aggregateType, elementType);
-		if (collection.wasSupplied()) {
-			return collection.get();
+		ResolvableType elementType = target.getType().asCollection().getGeneric();
+		IndexedCollectionSupplier result = new IndexedCollectionSupplier(
+				() -> CollectionFactory.createCollection(collectionType, 0));
+		bindIndexed(name, elementBinder, aggregateType, elementType, result);
+		if (result.wasSupplied()) {
+			return result.get();
 		}
 		return null;
 	}
diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/IndexedElementsBinder.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/IndexedElementsBinder.java
index 8b568266583..7faa52982e3 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/IndexedElementsBinder.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/IndexedElementsBinder.java
@@ -53,13 +53,20 @@ abstract class IndexedElementsBinder<T> extends AggregateBinder<T> {
 		return source == null || source instanceof IterableConfigurationPropertySource;
 	}
 
+	/**
+	 * Bind indexed elements to the supplied collection.
+	 * @param name The name of the property to bind
+	 * @param elementBinder the binder to use for elements
+	 * @param aggregateType the aggregate type, may be a collection or an array
+	 * @param elementType the element type
+	 * @param result the destination for results
+	 */
 	protected final void bindIndexed(ConfigurationPropertyName name,
-			AggregateElementBinder elementBinder, IndexedCollectionSupplier collection,
-			ResolvableType aggregateType, ResolvableType elementType) {
+			AggregateElementBinder elementBinder, ResolvableType aggregateType,
+			ResolvableType elementType, IndexedCollectionSupplier result) {
 		for (ConfigurationPropertySource source : getContext().getSources()) {
-			bindIndexed(source, name, elementBinder, collection, aggregateType,
-					elementType);
-			if (collection.wasSupplied() && collection.get() != null) {
+			bindIndexed(source, name, elementBinder, result, aggregateType, elementType);
+			if (result.wasSupplied() && result.get() != null) {
 				return;
 			}
 		}
@@ -134,7 +141,7 @@ abstract class IndexedElementsBinder<T> extends AggregateBinder<T> {
 	}
 
 	/**
-	 * {@link AggregateBinder.AggregateSupplier AggregateSupplier} for an index
+	 * {@link AggregateBinder.AggregateSupplier AggregateSupplier} for an indexed
 	 * collection.
 	 */
 	protected static class IndexedCollectionSupplier