Incorrect suggestion for for loop

I have this for loop:

for (int i = 0; i < messages.Length; i++)
{
    string singleMessage = messages[i];
    if (singleMessage.Contains("EOM"))
    {
        singleMessage = singleMessage.Replace("EOM", "");
    }
}

ReSharper suggests me to convert it to a foreach loop. The final result would be this:

foreach (string singleMessage in messages)
{    if (singleMessage.Contains("EOM"))
    {
        singleMessage = singleMessage.Replace("EOM", "");
    }
}

However now the singleMessage variable is readonly and it can not be assigned and the project will not compile.