diff --git a/data/lalr1.cc b/data/lalr1.cc
index afebda55..2c99aacf 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -314,8 +314,6 @@ b4_location_define])])[
       typedef basic_symbol<by_state> super_type;
       /// Construct an empty symbol.
       stack_symbol_type ();
-      /// Copy construct.
-      stack_symbol_type (const stack_symbol_type& that);
       /// Steal the contents from \a sym to build this.
       stack_symbol_type (state_type s, symbol_type& sym);
       /// Assignment, needed by push_back.
@@ -575,14 +573,6 @@ m4_if(b4_prefix, [yy], [],
   ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
   {}
 
-  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (const stack_symbol_type& that)
-    : super_type (that.state]b4_locations_if([, that.location])[)
-  {
-    ]b4_variant_if([b4_symbol_variant([that.type_get ()],
-                                      [value], [copy], [that.value])],
-                   [[value = that.value;]])[
-  }
-
   ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (state_type s, symbol_type& that)
     : super_type (s]b4_locations_if([, that.location])[)
   {