-field spec_version => '1.0';
-field indent_width => 2;
-field use_header => 1;
-field use_version => 0;
-field sort_keys => 1;
-field anchor_prefix => '';
-field dump_code => 0;
-field use_block => 0;
-field use_fold => 0;
-field compress_series => 1;
-field inline_series => 0;
-field use_aliases => 1;
-field purity => 0;
-field stringify => 0;
+has spec_version => default => sub {'1.0'};
+has indent_width => default => sub {2};
+has use_header => default => sub {1};
+has use_version => default => sub {0};
+has sort_keys => default => sub {1};
+has anchor_prefix => default => sub {''};
+has dump_code => default => sub {0};
+has use_block => default => sub {0};
+has use_fold => default => sub {0};
+has compress_series => default => sub {1};
+has inline_series => default => sub {0};
+has use_aliases => default => sub {1};
+has purity => default => sub {0};
+has stringify => default => sub {0};
+has quote_numeric_strings => default => sub {0};