diff --git a/lib/Slic3r/Fill/Concentric.pm b/lib/Slic3r/Fill/Concentric.pm
index 699b526d9..2a7c7823b 100644
--- a/lib/Slic3r/Fill/Concentric.pm
+++ b/lib/Slic3r/Fill/Concentric.pm
@@ -63,7 +63,7 @@ sub fill_surface {
         my $path = $loop->split_at_index($index);
         
         # clip the path to avoid the extruder to get exactly on the first point of the loop
-        $path->clip_end($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.15);
+        $path->clip_end(($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.15);
         
         push @paths, $path->points if @{$path->points};
     }
diff --git a/lib/Slic3r/Fill/Honeycomb.pm b/lib/Slic3r/Fill/Honeycomb.pm
index 70dd1e2ad..66fbd7ebb 100644
--- a/lib/Slic3r/Fill/Honeycomb.pm
+++ b/lib/Slic3r/Fill/Honeycomb.pm
@@ -21,7 +21,7 @@ sub fill_surface {
     # infill math
     my $min_spacing = scale $params{flow_spacing};
     my $distance = $min_spacing / $params{density};
-    my $overlap_distance = $self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.4;
+    my $overlap_distance = ($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.4;
     
     my $cache_id = sprintf "d%s_s%s_a%s",
         $params{density}, $params{flow_spacing}, $rotate_vector->[0][0];
diff --git a/lib/Slic3r/Fill/Rectilinear.pm b/lib/Slic3r/Fill/Rectilinear.pm
index b4569dbc8..d13321015 100644
--- a/lib/Slic3r/Fill/Rectilinear.pm
+++ b/lib/Slic3r/Fill/Rectilinear.pm
@@ -31,7 +31,7 @@ sub fill_surface {
         $flow_spacing = unscale $distance_between_lines;
     }
     
-    my $overlap_distance = $self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width * 0.4;
+    my $overlap_distance = ($self->layer ? $self->layer->flow->scaled_width : $Slic3r::flow->scaled_width) * 0.4;
     
     my $x = $bounding_box->[X1];
     my $is_line_pattern = $self->isa('Slic3r::Fill::Line');