diff --git a/MachMgrMachGroups.cpp b/MachMgrMachGroups.cpp
index 58897ab..95d5b49 100644
--- a/MachMgrMachGroups.cpp
+++ b/MachMgrMachGroups.cpp
@@ -80,6 +80,8 @@ MachMgr::GetMachGroupNewName( string& sName) const
   // verifico che il nome sia unico
    int nCount = 0 ;
    string sOrigName = sName ;
+   if ( sOrigName.rfind( "_1") == sOrigName.length() - 2)
+      sOrigName.erase( sOrigName.length() - 2) ;
    while ( GetMachGroupId( sName) != GDB_ID_NULL) {
       ++ nCount ;
       sName = sOrigName + "_" + ToString( nCount) ;
diff --git a/ToolsMgr.cpp b/ToolsMgr.cpp
index a65b8b6..41e45a1 100644
--- a/ToolsMgr.cpp
+++ b/ToolsMgr.cpp
@@ -316,7 +316,7 @@ ToolsMgr::GetToolNewName( string& sName) const
       sOrigName.erase( sOrigName.length() - 2) ;
    while ( GetTool( sName) != nullptr) {
       ++ nCount ;
-      sName = sOrigName + "-" + ToString( nCount) ;
+      sName = sOrigName + "_" + ToString( nCount) ;
    }
    return true ;
 }