lib/yaml-write-stream/stateful.rb in yaml-write-stream-2.0.0 vs lib/yaml-write-stream/stateful.rb in yaml-write-stream-2.0.1

@@ -165,10 +165,11 @@
     def write_sequence(key)
       write_scalar(key)
     end
 
     def write_key_value(key, value)
-      write_scalar(key)
+      quote_key = !!(key =~ /\A\d+\z/)
+      write_scalar(key, quote_key)
       write_scalar(value, true)
     end
 
     def close
       emitter.end_mapping