diff --git a/src/ca-module.hpp b/src/ca-module.hpp
index 3926d97..0b857b0 100644
--- a/src/ca-module.hpp
+++ b/src/ca-module.hpp
@@ -121,7 +121,7 @@
   std::list<InterestFilterHandle> m_interestFilterHandles;
 
   ECDHState m_ecdh;
-  uint8_t m_aesKey[32] = {0};
+  uint8_t m_aesKey[16] = {0};
 };
 
 } // namespace ndncert