diff --git a/src/security/command-interest-signer.cpp b/src/security/command-interest-signer.cpp
index 1dfe1ce..0d2f82f 100644
--- a/src/security/command-interest-signer.cpp
+++ b/src/security/command-interest-signer.cpp
@@ -25,6 +25,11 @@
 namespace ndn {
 namespace security {
 
+CommandInterestPreparer::CommandInterestPreparer()
+  : m_lastUsedTimestamp(0)
+{
+}
+
 Name
 CommandInterestPreparer::prepareCommandInterestName(Name name)
 {
diff --git a/src/security/command-interest-signer.hpp b/src/security/command-interest-signer.hpp
index 7033b3f..6c5e2ce 100644
--- a/src/security/command-interest-signer.hpp
+++ b/src/security/command-interest-signer.hpp
@@ -41,6 +41,8 @@
 class CommandInterestPreparer : noncopyable
 {
 public:
+  CommandInterestPreparer();
+
   /**
    * @brief Prepare name of the CommandInterest
    *