diff --git a/src/api/c++/z3++.h b/src/api/c++/z3++.h
index d42e70c75..625964347 100644
--- a/src/api/c++/z3++.h
+++ b/src/api/c++/z3++.h
@@ -106,8 +106,8 @@ namespace z3 {
     */
     class config {
         Z3_config    m_cfg;
-        config(config const & s) = delete;
-        config & operator=(config const & s) = delete;
+        config(config const &) = delete;
+        config & operator=(config const &) = delete;
     public:
         config() { m_cfg = Z3_mk_config(); }
         ~config() { Z3_del_config(m_cfg); }
@@ -170,8 +170,8 @@ namespace z3 {
         }
 
 
-        context(context const & s) = delete;
-        context & operator=(context const & s) = delete;
+        context(context const &) = delete;
+        context & operator=(context const &) = delete;
 
         friend class scoped_context;
         context(Z3_context c) { set_context(c); }
@@ -395,8 +395,8 @@ namespace z3 {
     class array {
         std::unique_ptr<T[]> m_array;
         unsigned m_size;
-        array(array const & s) = delete;
-        array & operator=(array const & s) = delete;
+        array(array const &) = delete;
+        array & operator=(array const &) = delete;
     public:
         array(unsigned sz):m_array(new T[sz]),m_size(sz) {}
         template<typename T2>