diff --git a/tools/peek/ndn-poke.cpp b/tools/peek/ndn-poke.cpp
index ceb49b3..7a1eb7b 100644
--- a/tools/peek/ndn-poke.cpp
+++ b/tools/peek/ndn-poke.cpp
@@ -27,6 +27,8 @@
 
 #include "core/version.hpp"
 
+#include <ndn-cxx/security/signing-helpers.hpp>
+
 #include <sstream>
 
 namespace ndn {