diff --git a/core/java/com/google/android/mms/pdu/PduPersister.java b/core/java/com/google/android/mms/pdu/PduPersister.java
index 568aeb718b63c..2a1f23abbad16 100644
--- a/core/java/com/google/android/mms/pdu/PduPersister.java
+++ b/core/java/com/google/android/mms/pdu/PduPersister.java
@@ -855,6 +855,8 @@ public class PduPersister {
         if (subject != null) {
             values.put(Mms.SUBJECT, toIsoString(subject.getTextString()));
             values.put(Mms.SUBJECT_CHARSET, subject.getCharacterSet());
+        } else {
+            values.put(Mms.SUBJECT, "");
         }
         
         long messageSize = sendReq.getMessageSize();