diff --git a/lib/logstash/codecs/fluent.rb b/lib/logstash/codecs/fluent.rb
index 92175f3..dfaaf8d 100644
--- a/lib/logstash/codecs/fluent.rb
+++ b/lib/logstash/codecs/fluent.rb
@@ -72,7 +72,7 @@ def decode_event(data, &block)
         map = entry[1]
         event = LogStash::Event.new(map.merge(
                                       LogStash::Event::TIMESTAMP => LogStash::Timestamp.at(epochtime),
-                                      "tags" => [ tag ]
+                                      "tags" => map.has_key?("tags") ? map["tags"] + [ tag ] : [ tag ]
                                     ))
         yield event
       end
@@ -83,7 +83,7 @@ def decode_event(data, &block)
         map = entry[1]
         event = LogStash::Event.new(map.merge(
                                       LogStash::Event::TIMESTAMP => LogStash::Timestamp.at(epochtime),
-                                      "tags" => [ tag ]
+                                      "tags" => map.has_key?("tags") ? map["tags"] + [ tag ] : [ tag ]
                                     ))
         yield event
       end
@@ -93,7 +93,7 @@ def decode_event(data, &block)
       map = data[2]
       event = LogStash::Event.new(map.merge(
                                     LogStash::Event::TIMESTAMP => LogStash::Timestamp.at(epochtime),
-                                    "tags" => [ tag ]
+                                    "tags" => map.has_key?("tags") ? map["tags"] + [ tag ] : [ tag ]
                                   ))
       yield event
     else
diff --git a/spec/codecs/fluent_spec.rb b/spec/codecs/fluent_spec.rb
index c85cd1f..49d5b83 100644
--- a/spec/codecs/fluent_spec.rb
+++ b/spec/codecs/fluent_spec.rb
@@ -38,6 +38,7 @@
     it "should decode without errors" do
       subject.decode(message) do |event|
         expect(event.get("name")).to eq("foo")
+        expect(event.get("tags")).to eq("mytag")
       end
     end
 
@@ -63,6 +64,7 @@
 
       subject.decode(message) do |event|
         expect(event.get("name")).to eq("foo")
+        expect(event.get("tags")).to eq("mytag")
         count += 1
       end