diff --git a/lib/Diskstats.pm b/lib/Diskstats.pm
index ffc018c7..90385e13 100644
--- a/lib/Diskstats.pm
+++ b/lib/Diskstats.pm
@@ -133,11 +133,15 @@ sub set_filter_zeroed_rows {
 }
 
 sub sample_time {
+   my ($self) = @_;
+   return $self->{sample_time};
+}
+
+sub set_sample_time {
    my ($self, $new_val) = @_;
    if (defined($new_val)) {
       $self->{sample_time} = $new_val;
    }
-   return $self->{sample_time};
 }
 
 sub interactive {
diff --git a/lib/DiskstatsMenu.pm b/lib/DiskstatsMenu.pm
index a422ec8a..41314bd4 100644
--- a/lib/DiskstatsMenu.pm
+++ b/lib/DiskstatsMenu.pm
@@ -386,8 +386,9 @@ sub get_new_value_for {
       die "Invalid timeout: $new_interval"
          unless looks_like_number($new_interval);
 
-      if ( $args{options}->{current_group_by_obj}->can($looking_for) ) {
-         $args{options}->{current_group_by_obj}->$looking_for($new_interval);
+      if ( my $setter = $args{options}->{current_group_by_obj}->can("set_$looking_for") )
+      {
+         $args{options}->{current_group_by_obj}->$setter($new_interval);
       }
       $args{options}->{OptionParser}->set($looking_for_o, $new_interval);
       return $new_interval;