diff --git a/Check.pm b/Check.pm
index 7a59d40..5fcc5b7 100644
--- a/Check.pm
+++ b/Check.pm
@@ -104,7 +104,7 @@ sub action
       if ( $Backups[-4] ) { # There are enough backup ?
 
         # TOO BIG ? If the size is 6 times higher than usual :
-        if ( $new_size > ($new_size_q3 + $new_size_q3 - $new_size_q1) * 1.5 and $new_size > $new_size_avg * 6 ) {
+        if ( $new_size > ($new_size_q3 + ($new_size_q3 - $new_size_q1) ) * 1.5 and $new_size > $new_size_avg * 6 ) {
           $toobig = 1;
         }