diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/packet/DataForm.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/packet/DataForm.java
index d56214d31..0457e69f3 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/packet/DataForm.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/packet/DataForm.java
@@ -494,6 +494,9 @@ public final class DataForm implements ExtensionElement {
          * @return a reference to this builder.
          */
         public Builder addItem(Item item) {
+            if (items == null) {
+                items = new ArrayList<>();
+            }
             items.add(item);
             return this;
         }