diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 9a003521b..f1e8f2235 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -80,7 +80,7 @@ use constant SMALL_PERIMETER_LENGTH => (6.5 / SCALING_FACTOR) * 2 * PI;
 use constant LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER => 0.15;
 use constant INFILL_OVERLAP_OVER_SPACING  => 0.45;
 use constant EXTERNAL_INFILL_MARGIN => 3;
-use constant INSET_OVERLAP_TOLERANCE => 0.2;
+use constant INSET_OVERLAP_TOLERANCE => 0.4;
 
 # keep track of threads we created
 my @my_threads = ();