diff --git a/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoder.java b/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoder.java
index 5dadcf4..1d920be 100644
--- a/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoder.java
+++ b/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoder.java
@@ -74,7 +74,7 @@ class XMLValuesEncoder {
         }
     }
     void encodeNullValue(Entry entry){
-        // Nothing to do
+        entry.setValueAsString("");
     }
     void encodeLiteralEmptyValue(Entry entry, String value){
         entry.setValueAsRaw(ValueType.NULL, 0);
diff --git a/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoderBag.java b/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoderBag.java
index 859be8f..8a284ab 100644
--- a/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoderBag.java
+++ b/src/main/java/com/reandroid/apk/xmlencoder/XMLValuesEncoderBag.java
@@ -44,4 +44,9 @@ class XMLValuesEncoderBag extends XMLValuesEncoder{
     int getChildesCount(XMLElement element){
         return element.getChildesCount();
     }
+
+    @Override
+    void encodeNullValue(Entry entry){
+        // Nothing to do
+    }
 }