diff --git a/src/main/java/graphql/language/InputValueDefinition.java b/src/main/java/graphql/language/InputValueDefinition.java
index 4169866be7..477e52e029 100644
--- a/src/main/java/graphql/language/InputValueDefinition.java
+++ b/src/main/java/graphql/language/InputValueDefinition.java
@@ -81,7 +81,9 @@ public List<Directive> getDirectives() {
     public List<Node> getChildren() {
         List<Node> result = new ArrayList<>();
         result.add(type);
-        result.add(defaultValue);
+        if (defaultValue != null) {
+            result.add(defaultValue);
+        }
         result.addAll(directives);
         return result;
     }