diff --git a/lib/AI/DecisionTree.pm b/lib/AI/DecisionTree.pm

index 561999f..355d26f 100644

--- a/lib/AI/DecisionTree.pm

+++ b/lib/AI/DecisionTree.pm

@@ -343,7 +343,7 @@ sub get_result {

 sub as_graphviz {

   my ($self, %args) = @_;

   my $colors = delete $args{leaf_colors} || {};

-  require GraphViz;

+  eval { require GraphViz; } or die $@;

   my $g = GraphViz->new(%args);

   my $id = 1;