diff --git a/tests/unit/encryptor.t.cpp b/tests/unit/encryptor.t.cpp
index d9bafba..02ae88b 100644
--- a/tests/unit/encryptor.t.cpp
+++ b/tests/unit/encryptor.t.cpp
@@ -23,10 +23,12 @@
 #include "tests/io-key-chain-fixture.hpp"
 #include "tests/unit/static-data.hpp"
 
-#include <iostream>
+#include <ndn-cxx/security/signing-helpers.hpp>
 #include <ndn-cxx/util/dummy-client-face.hpp>
 #include <ndn-cxx/util/string-helper.hpp>
 
+#include <iostream>
+
 namespace ndn {
 namespace nac {
 namespace tests {