diff --git a/src/security/key-chain.cpp b/src/security/key-chain.cpp
index 424a8e8..d3e7a6a 100644
--- a/src/security/key-chain.cpp
+++ b/src/security/key-chain.cpp
@@ -17,6 +17,10 @@
 
 using namespace std;
 using namespace ndn::ptr_lib;
+#if NDN_CPP_HAVE_STD_FUNCTION
+// In the std library, the placeholders are in a different namespace than boost.                                    
+using namespace func_lib::placeholders;
+#endif
 
 namespace ndn {