diff --git a/etc/logstash-grep.yaml b/etc/logstash-grep.yaml
index f23208404..4574a55af 100644
--- a/etc/logstash-grep.yaml
+++ b/etc/logstash-grep.yaml
@@ -21,7 +21,7 @@ filters:
           - nagios
           - test
       - match:
-          message: r/foo.*bar/i
+          message: (?i)foo.*bar
           program: test
         add_fields:
           nagios_alert: foo_alert
diff --git a/test/logstash/filters/test_grep.rb b/test/logstash/filters/test_grep.rb
index c88b95590..8bd3abe09 100644
--- a/test/logstash/filters/test_grep.rb
+++ b/test/logstash/filters/test_grep.rb
@@ -67,7 +67,7 @@ class TestFilterGrep < Test::Unit::TestCase
 
   def test_single_match_regexp
     test_name "single_match_regexp"
-    config [{"match" => {"str" => /test.*foo/i}}]
+    config [{"match" => {"str" => "(?i)test.*foo"}}]
 
     event = LogStash::Event.new
     event.type = @typename
@@ -78,7 +78,7 @@ class TestFilterGrep < Test::Unit::TestCase
 
   def test_single_match_regexp_drop
     test_name "single_match_regexp_drop"
-    config [{"match" => {"str" => /test.*foo/}}]
+    config [{"match" => {"str" => "test.*foo"}}]
 
     event = LogStash::Event.new
     event.type = @typename