diff --git a/lib/instapaper/api/oauth.rb b/lib/instapaper/api/oauth.rb
index 3c74940..52a0022 100644
--- a/lib/instapaper/api/oauth.rb
+++ b/lib/instapaper/api/oauth.rb
@@ -9,7 +9,7 @@ module Instapaper
       def access_token(username, password)
         response = perform_post_with_unparsed_response('/api/1.1/oauth/access_token', x_auth_username: username, x_auth_password: password, x_auth_mode: 'client_auth')
         parsed_response = QLineParser.parse(response)
-        fail Instapaper::Error::OAuthError, parsed_response['error'] if parsed_response.key?('error')
+        raise Instapaper::Error::OAuthError, parsed_response['error'] if parsed_response.key?('error')
         Instapaper::Credentials.new(parsed_response)
       end
     end
diff --git a/lib/instapaper/http/response.rb b/lib/instapaper/http/response.rb
index 0947a83..15da2a5 100644
--- a/lib/instapaper/http/response.rb
+++ b/lib/instapaper/http/response.rb
@@ -39,9 +39,9 @@ module Instapaper
         return if response.status.ok?
 
         if Instapaper::Error::CODES.include?(response.status.code)
-          fail Instapaper::Error.from_response(response.status.code, path)
+          raise Instapaper::Error.from_response(response.status.code, path)
         else
-          fail Instapaper::Error, 'Unknown Error'
+          raise Instapaper::Error, 'Unknown Error'
         end
       end
 
@@ -53,10 +53,10 @@ module Instapaper
 
       def fail_if_body_contains_error
         return unless parsed.is_a?(Array)
-        return unless parsed.size > 0
+        return if parsed.empty?
         return unless parsed.first['type'] == 'error'
 
-        fail Instapaper::Error.from_response(parsed.first['error_code'], @path)
+        raise Instapaper::Error.from_response(parsed.first['error_code'], @path)
       end
     end
   end