diff --git a/ndn-cpp/c/encoding/BinaryXMLPublisherPublicKeyDigest.c b/ndn-cpp/c/encoding/BinaryXMLPublisherPublicKeyDigest.c
index b1ee3f8..00e3582 100644
--- a/ndn-cpp/c/encoding/BinaryXMLPublisherPublicKeyDigest.c
+++ b/ndn-cpp/c/encoding/BinaryXMLPublisherPublicKeyDigest.c
@@ -33,3 +33,22 @@
   
   return 0;
 }
+
+ndn_Error ndn_decodeOptionalBinaryXMLPublisherPublicKeyDigest
+  (struct ndn_PublisherPublicKeyDigest *publisherPublicKeyDigest, struct ndn_BinaryXMLDecoder *decoder)
+{
+  int gotExpectedTag;
+  ndn_Error error; 
+  if (error = ndn_BinaryXMLDecoder_peekDTag(decoder, ndn_BinaryXML_DTag_PublisherPublicKeyDigest, &gotExpectedTag))
+    return error;
+  if (gotExpectedTag) {
+    if (error = ndn_decodeBinaryXMLPublisherPublicKeyDigest(publisherPublicKeyDigest, decoder))
+      return error;
+  }
+  else {
+    publisherPublicKeyDigest->publisherPublicKeyDigest = 0;
+    publisherPublicKeyDigest->publisherPublicKeyDigestLength = 0;
+  }
+  
+  return 0;
+}