diff --git a/java/core/src/main/java/com/google/protobuf/FieldSet.java b/java/core/src/main/java/com/google/protobuf/FieldSet.java
index d52aede95803..8306c471cca7 100644
--- a/java/core/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
@@ -1078,8 +1078,7 @@ public void setField(final T descriptor, Object value) {
 
         // Wrap the contents in a new list so that the caller cannot change
         // the list's contents after setting it.
-        final List newList = new ArrayList();
-        newList.addAll((List) value);
+        final List newList = new ArrayList((List) value);
         for (final Object element : newList) {
           verifyType(descriptor.getLiteType(), element);
           hasNestedBuilders = hasNestedBuilders || element instanceof MessageLite.Builder;