diff --git a/tests_boost/test-encode-decode-data.cpp b/tests_boost/test-encode-decode-data.cpp
index 11e5a83..a89011b 100644
--- a/tests_boost/test-encode-decode-data.cpp
+++ b/tests_boost/test-encode-decode-data.cpp
@@ -145,12 +145,8 @@
   Block signatureInfo(Tlv::SignatureInfo);
   // SignatureType
   {
-    OBufferStream os;
-    Tlv::writeVarNumber(os, Tlv::SignatureType);
-    Tlv::writeVarNumber(os, Tlv::sizeOfNonNegativeInteger(Signature::Sha256WithRsa));
-    Tlv::writeNonNegativeInteger(os, Signature::Sha256WithRsa);
-    
-    signatureInfo.push_back(Block(os.buf()));
+    signatureInfo.push_back
+      (nonNegativeIntegerBlock(Tlv::SignatureType, Signature::Sha256WithRsa));
   }
   // KeyLocator
   {