diff --git a/codegenplug/symbols/structmodule.vala b/codegenplug/symbols/structmodule.vala
index 362dd846..fde026b0 100644
--- a/codegenplug/symbols/structmodule.vala
+++ b/codegenplug/symbols/structmodule.vala
@@ -81,6 +81,8 @@ public class codegenplug.StructModule : shotodolplug.Module {
 		decl_space.add_type_definition (instance_struct);
 		var func_macro = new CCodeMacroReplacement("%s(x,xindex,y,yindex)".printf(resolve.get_ccode_free_function(st)), "({%s(x,xindex,y,yindex);})".printf(resolve.get_ccode_copy_function(st)));
 		decl_space.add_type_declaration (func_macro);
+		var dup_func_macro = new CCodeMacroReplacement("%s(x)".printf(resolve.get_ccode_dup_function(st)), "({x;})");
+		decl_space.add_type_declaration (dup_func_macro);
 	}
 
 	void generate_struct_copy_function (Struct st) {