In encodeExclude, need return 0, not return.
diff --git a/ndn-cpp/c/encoding/BinaryXMLInterest.c b/ndn-cpp/c/encoding/BinaryXMLInterest.c
index b9de3d6..270e13b 100644
--- a/ndn-cpp/c/encoding/BinaryXMLInterest.c
+++ b/ndn-cpp/c/encoding/BinaryXMLInterest.c
@@ -12,7 +12,7 @@
static ndn_Error encodeExclude(struct ndn_Exclude *exclude, struct ndn_BinaryXMLEncoder *encoder)
{
if (exclude->nEntries == 0)
- return;
+ return 0;
ndn_Error error;
if (error = ndn_BinaryXMLEncoder_writeElementStartDTag(encoder, ndn_BinaryXML_DTag_Exclude))