diff --git a/src/crypto-secret/stateful.cr b/src/crypto-secret/stateful.cr
index c552645..c8aeeb4 100644
--- a/src/crypto-secret/stateful.cr
+++ b/src/crypto-secret/stateful.cr
@@ -105,6 +105,12 @@ module Crypto::Secret
       @state = State::Wiped
     end
 
+    def dup
+      super.tap do |obj|
+        obj.set_state @state
+      end
+    end
+
     protected abstract def readwrite_impl : Nil
     protected abstract def readonly_impl : Nil
     protected abstract def noaccess_impl : Nil