diff --git a/seckey.h b/seckey.h
index 3a682ea0..38fd14a8 100644
--- a/seckey.h
+++ b/seckey.h
@@ -10,6 +10,7 @@
 #include "cryptlib.h"
 #include "misc.h"
 #include "simple.h"
+#include "stdcpp.h"
 
 #if CRYPTOPP_MSC_VERSION
 # pragma warning(push)