diff --git a/src/main/java/fi/methics/laverca/rest/json/MSS_SignatureReq.java b/src/main/java/fi/methics/laverca/rest/json/MSS_SignatureReq.java
index 0310686..c4ec9e9 100644
--- a/src/main/java/fi/methics/laverca/rest/json/MSS_SignatureReq.java
+++ b/src/main/java/fi/methics/laverca/rest/json/MSS_SignatureReq.java
@@ -47,7 +47,7 @@ public MSS_SignatureReq(final String msisdn, final DTBS dtbs, final String dtbd)
         this.MobileUser.MSISDN = msisdn;
         
         this.DataToBeSigned = new Data();
-        this.DataToBeSigned.Data     = dtbs.getText();
+        this.DataToBeSigned.Data     = dtbs.getText() != null ? dtbs.getText() : Base64.getEncoder().encodeToString(dtbs.toBytes());
         this.DataToBeSigned.Encoding = dtbs.getEncoding();
         this.DataToBeSigned.MimeType = dtbs.getMimetype();