diff --git a/lib/Slic3r/GUI/SkeinPanel.pm b/lib/Slic3r/GUI/SkeinPanel.pm
index 19209aef5..e42d14507 100644
--- a/lib/Slic3r/GUI/SkeinPanel.pm
+++ b/lib/Slic3r/GUI/SkeinPanel.pm
@@ -159,8 +159,10 @@ sub do_slice {
             },
         );
         {
-            local $SIG{__WARN__} = $self->catch_warning;
+            my @warnings = ();
+            local $SIG{__WARN__} = sub { push @warnings, $_[0] };
             $skein->go;
+            $self->catch_warning->($_) for @warnings;
         }
         $process_dialog->Destroy;
         undef $process_dialog;