README.md in arx-0.3.0 vs README.md in arx-0.3.1

@@ -285,16 +285,16 @@
 
 # Paper's comment
 paper.comment?
 #=> false
 paper.comment
-#=> Arx::MissingFieldError (This arXiv paper is missing the `comment` field)
+#=> Arx::Error::MissingField (This arXiv paper is missing the `comment` field)
 
 # Paper's journal reference
 paper.journal?
 #=> false
 paper.journal
-#=> Arx::MissingFieldError (This arXiv paper is missing the `journal` field)
+#=> Arx::Error::MissingField (This arXiv paper is missing the `journal` field)
 
 # Paper's PDF URL
 paper.pdf?
 #=> true
 paper.pdf_url
\ No newline at end of file