diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 773d12775..eaca434b2 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -1545,7 +1545,7 @@ namespace tools
       er.message = "Failed to add address book entry";
       return false;
     }
-    res.index = m_wallet->get_address_book().size();
+    res.index = m_wallet->get_address_book().size() - 1;
     return true;
   }
   //------------------------------------------------------------------------------------------------------------------------------