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

@@ -101,10 +101,11 @@
       super()
     end
 
     def write_key_value(key, value)
       @first = false
-      write_scalar(key)
+      quote_key = !!(key =~ /\A\d+\z/)
+      write_scalar(key, quote_key)
       write_scalar(value, true)
     end
   end
 
   class YieldingSequenceWriter < YieldingWriter