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;