diff --git a/src/util/random.hpp b/src/util/random.hpp
index bb5a3a6..f7dbc22 100644
--- a/src/util/random.hpp
+++ b/src/util/random.hpp
@@ -14,6 +14,9 @@
 uint32_t
 generateWord32();
 
+uint64_t
+generateWord64();
+
 } // namespace random
 } // namespace ndn