diff --git a/ndn-cpp/security/key-chain.cpp b/ndn-cpp/security/key-chain.cpp
index c456036..4a19869 100644
--- a/ndn-cpp/security/key-chain.cpp
+++ b/ndn-cpp/security/key-chain.cpp
@@ -137,7 +137,7 @@
   const unsigned char *publicKeyDer;
   unsigned int publicKeyDerLength;
   if (data.getSignature().getKeyLocator().getType() == ndn_KeyLocatorType_KEY) {
-    publicKeyDer = &data.getSignature().getKeyLocator().getKeyData().front();
+    publicKeyDer = data.getSignature().getKeyLocator().getKeyData().buf();
     publicKeyDerLength = data.getSignature().getKeyLocator().getKeyData().size();
   }
   else