diff --git a/tools/ndnsec/list.cpp b/tools/ndnsec/list.cpp
index 336a574..ec38f6e 100644
--- a/tools/ndnsec/list.cpp
+++ b/tools/ndnsec/list.cpp
@@ -22,7 +22,7 @@
 #include "ndnsec.hpp"
 #include "util.hpp"
 
-#include <ndn-cxx/util/indented-stream.hpp>
+#include "ndn-cxx/util/indented-stream.hpp"
 
 namespace ndn {
 namespace ndnsec {
diff --git a/tools/ndnsec/main.cpp b/tools/ndnsec/main.cpp
index 0db6d54..d2bc281 100644
--- a/tools/ndnsec/main.cpp
+++ b/tools/ndnsec/main.cpp
@@ -22,8 +22,8 @@
 #include "ndnsec.hpp"
 #include "util.hpp"
 
-#include <ndn-cxx/util/logger.hpp>
-#include <ndn-cxx/version.hpp>
+#include "ndn-cxx/util/logger.hpp"
+#include "ndn-cxx/version.hpp"
 
 #include <boost/exception/get_error_info.hpp>
 
diff --git a/tools/ndnsec/util.cpp b/tools/ndnsec/util.cpp
index b97e934..f5069e7 100644
--- a/tools/ndnsec/util.cpp
+++ b/tools/ndnsec/util.cpp
@@ -21,7 +21,7 @@
 
 #include "util.hpp"
 
-#include <ndn-cxx/security/detail/openssl.hpp>
+#include "ndn-cxx/security/detail/openssl.hpp"
 
 namespace ndn {
 namespace ndnsec {
diff --git a/tools/ndnsec/util.hpp b/tools/ndnsec/util.hpp
index 65b88e7..8ea6976 100644
--- a/tools/ndnsec/util.hpp
+++ b/tools/ndnsec/util.hpp
@@ -22,11 +22,11 @@
 #ifndef NDN_TOOLS_NDNSEC_UTIL_HPP
 #define NDN_TOOLS_NDNSEC_UTIL_HPP
 
-#include <ndn-cxx/encoding/buffer-stream.hpp>
-#include <ndn-cxx/security/key-chain.hpp>
-#include <ndn-cxx/security/transform.hpp>
-#include <ndn-cxx/security/v2/additional-description.hpp>
-#include <ndn-cxx/util/io.hpp>
+#include "ndn-cxx/encoding/buffer-stream.hpp"
+#include "ndn-cxx/security/key-chain.hpp"
+#include "ndn-cxx/security/transform.hpp"
+#include "ndn-cxx/security/v2/additional-description.hpp"
+#include "ndn-cxx/util/io.hpp"
 
 #include <fstream>
 #include <iostream>