diff --git a/Check.pm b/Check.pm
index eaa24f1..7a59d40 100644
--- a/Check.pm
+++ b/Check.pm
@@ -109,7 +109,7 @@ sub action
         }
 
         # TOO SMALL ? If the size is 3 times lower than usual :
-        if ( $new_size < ($new_size_q1 - $new_size_q3 - $new_size_q1) * 1.5 and $new_size < $new_size_avg / 3 ) {
+        if ( $new_size < ($new_size_q1 - ($new_size_q3 - $new_size_q1) ) * 1.5 and $new_size < $new_size_avg / 3 ) {
           $toosmall = 1;
         }