diff --git a/include/files.cpp b/include/files.cpp
index 60a5de2c4..848a54f86 100755
--- a/include/files.cpp
+++ b/include/files.cpp
@@ -606,8 +606,6 @@ void TTrec::update_keydef (int key, const char *desc)
   {                          
     const char * dup = s.get();
     _rec->Ky[key].DupKeys = (dup && *dup != ' ');
-    if (key == 0 && _rec->Ky[key].DupKeys)
-      fatal_box("L'indice numero 1 non puo' avere chiavi duplicate.");
     TCodearray & c = expr.code ();
     c.begin ();
     int n = 0;