diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index 39bfef4c2..99af25526 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -29,8 +29,8 @@ use constant I_FACET_EDGE       => 6;
 use constant FE_TOP             => 0;
 use constant FE_BOTTOM          => 1;
 
-# always make sure BUILD is idempotent
-sub BUILD {
+# always make sure this method is idempotent
+sub analyze {
     my $self = shift;
     
     @{$self->edges} = ();
@@ -145,6 +145,8 @@ sub clean {
 sub check_manifoldness {
     my $self = shift;
     
+    $self->analyze;
+    
     # look for any edges not connected to exactly two facets
     my ($first_bad_edge_id) =
         grep { @{ $self->edges_facets->[$_] } != 2 } 0..$#{$self->edges_facets};
@@ -154,6 +156,10 @@ sub check_manifoldness {
             map @{$self->vertices->[$_]}, @{$self->edges->[$first_bad_edge_id]};
         return 0;
     }
+    
+    # empty the edges array as we don't really need it anymore
+    @{$self->edges} = ();
+    
     return 1;
 }