MySQL表行不会UPDATE

I am trying to update a column in a row in a MySQL table. The column is the 'votes' column and when someone submits an HTML form there is a hidden input with a value of "1" that gets submit and posted. This is the code I am using to try to update the vote count:

if(isset($_POST['image_id']) && isset($_POST['vote'])){
    $image_id = $mysqli->real_escape_string($_POST['image_id']);
    $vote = $mysqli->real_escape_string($_POST['vote']);

    $sql_users_vote = "SELECT * FROM users WHERE id='$image_id'";
    $result_users_vote = $mysqli->query($sql_users_vote);
    $row_vote = mysqli_fetch_array($result_users_vote);
    $votes_count = $row_vote['votes'];
    $new_votes = $votes_count + $vote;

    $sql_vote = "UPDATE users WHERE id='$image_id' SET votes=$new_votes";
   $result_vote = $mysqli->query($sql_vote);
 }

I have echo'ed out the variable up until $sql_vote and $image_id, $vote, $votes_count and $new_votes all echo out the correct values. I'm guessing that there is a problem in the UPDATE syntax. I've checked it over and over but can't seem to find anything. I know that I don't have quotes around $new_votes in the UPDATE because I believe that is correct syntax. I've tried it with quotes and it doesn't work that way either.

Can someone help me identify the problem? Thanks!

$sql_vote = "UPDATE users SET votes=$new_votes WHERE id='$image_id'";

Doesn't the SET come before the WHERE?

$sql_vote = "UPDATE users SET votes = $new_votes WHERE id = '$image_id'"

Or does it not matter?