diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cc79e9..7cb439d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 3.1.1
+  - Docs: cover existing ECS `v8` alias to `v1` implementation
+
 ## 3.1.0
   - Add ECS support. Add `target` option [#20](https://github.com/logstash-plugins/logstash-codec-es_bulk/pull/20)
 
diff --git a/docs/index.asciidoc b/docs/index.asciidoc
index 40eebee..4307bfc 100644
--- a/docs/index.asciidoc
+++ b/docs/index.asciidoc
@@ -58,7 +58,7 @@ When ECS is enabled, the metadata is stored in the `[@metadata][codec][es_bulk]`
 * Value type is <<string,string>>
 * Supported values are:
 ** `disabled`: unstructured metadata added at @metadata
-** `v1`: uses `[@metadata][codec][es_bulk]` fields
+** `v1`,`v8`: uses `[@metadata][codec][es_bulk]` fields
 
 Controls this plugin's compatibility with the {ecs-ref}[Elastic Common Schema (ECS)].
 
diff --git a/logstash-codec-es_bulk.gemspec b/logstash-codec-es_bulk.gemspec
index ad44671..fec9ba0 100644
--- a/logstash-codec-es_bulk.gemspec
+++ b/logstash-codec-es_bulk.gemspec
@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-codec-es_bulk'
-  s.version         = '3.1.0'
+  s.version         = '3.1.1'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Reads the Elasticsearch bulk format into separate events, along with metadata"
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"
diff --git a/spec/codecs/es_bulk_spec.rb b/spec/codecs/es_bulk_spec.rb
index 155e7bc..023b8bb 100644
--- a/spec/codecs/es_bulk_spec.rb
+++ b/spec/codecs/es_bulk_spec.rb
@@ -5,7 +5,7 @@
 require 'logstash/plugin_mixins/ecs_compatibility_support/spec_helper'
 
 describe LogStash::Codecs::ESBulk, :ecs_compatibility_support  do
-  ecs_compatibility_matrix(:disabled, :v1, :v8) do |ecs_select|
+  ecs_compatibility_matrix(:disabled, :v1, :v8 => :v1) do |ecs_select|
     before(:each) do
       allow_any_instance_of(described_class).to receive(:ecs_compatibility).and_return(ecs_compatibility)
     end
@@ -26,7 +26,7 @@
       { "doc" : {"field2" : "value2"} }
         HERE
 
-        metadata_field = '[@metadata][codec][es_bulk]'
+        metadata_field = ecs_select[disabled: '[@metadata]', v1:'[@metadata][codec][es_bulk]']
 
         count = 0
         subject.decode(data) do |event|
@@ -51,7 +51,7 @@
         end
         insist { count } == 4
       end
-    end if ecs_select.active_mode != :disabled
+    end
 
     context "fail to process non-bulk event then continue" do
       it "continues after a fail" do