diff --git a/lib/fluent/plugin/parser_apache2.rb b/lib/fluent/plugin/parser_apache2.rb
index 4393f0a52b..4bd1c3d419 100644
--- a/lib/fluent/plugin/parser_apache2.rb
+++ b/lib/fluent/plugin/parser_apache2.rb
@@ -21,7 +21,7 @@ module Plugin
     class Apache2Parser < Parser
       Plugin.register_parser('apache2', self)
 
-      REGEXP = /^(?<host>[^ ]*) [^ ]* (?<user>[^ ]*) \[(?<time>[^\]]*)\] "(?<method>\S+)(?: +(?<path>(?:[^\"]|\\.)*?)(?: +\S*)?)?" (?<code>[^ ]*) (?<size>[^ ]*)(?: "(?<referer>(?:[^\"]|\\.)*)" "(?<agent>(?:[^\"]|\\.)*)")?$/
+      REGEXP = /^(?<host>[^ ]*) [^ ]* (?<user>[^ ]*) \[(?<time>[^\]]*)\] "(?<method>\S+)(?: +(?<path>(?:[^\"]|\\")*?)(?: +\S*)?)?" (?<code>[^ ]*) (?<size>[^ ]*)(?: "(?<referer>(?:[^\"]|\\")*)" "(?<agent>(?:[^\"]|\\")*)")?$/
       TIME_FORMAT = "%d/%b/%Y:%H:%M:%S %z"
 
       def initialize