diff --git a/src/crypto/crypto-sugar.h b/src/crypto/crypto-sugar.h
index 545f3aab..14c168e8 100644
--- a/src/crypto/crypto-sugar.h
+++ b/src/crypto/crypto-sugar.h
@@ -429,7 +429,7 @@ namespace crypto
         zero();
     }
 
-    explicit point_t(tag_zero&)
+    explicit point_t(tag_zero&&)
     {
       zero();
     }