diff --git a/logstash-core/lib/logstash/patches/clamp.rb b/logstash-core/lib/logstash/patches/clamp.rb
index ad690d776d5..1fc953718c4 100644
--- a/logstash-core/lib/logstash/patches/clamp.rb
+++ b/logstash-core/lib/logstash/patches/clamp.rb
@@ -79,16 +79,13 @@ def define_deprecated_writer_for(option, opts, &block)
           new_flag = opts[:new_flag]
           new_value = opts.fetch(:new_value, value)
           passthrough = opts.fetch(:passthrough, false)
-          deprecated_msg = opts[:deprecated_msg]
+          obsoleted_version = opts[:obsoleted_version]
 
-          LogStash::DeprecationMessage.instance <<
-            if new_flag
-             "DEPRECATION WARNING: The flag #{option.switches} has been deprecated, please use \"--#{new_flag}=#{new_value}\" instead."
-            elsif deprecated_msg
-              deprecated_msg
-            else
-              "DEPRECATION WARNING: The flag #{option.switches} has been deprecated and may be removed in a future release."
-            end
+          dmsg = "DEPRECATION WARNING: The flag #{option.switches} has been deprecated"
+          dmsg += obsoleted_version.nil? ? " and may be removed in a future release" : " and will be removed in version #{obsoleted_version}"
+          dmsg += new_flag.nil? ? ".": ", please use \"--#{new_flag}=#{new_value}\" instead."
+
+          LogStash::DeprecationMessage.instance << dmsg
 
           if passthrough
             LogStash::SETTINGS.set(option.attribute_name, value)
diff --git a/logstash-core/lib/logstash/runner.rb b/logstash-core/lib/logstash/runner.rb
index 27d3e6005ed..20119d90467 100644
--- a/logstash-core/lib/logstash/runner.rb
+++ b/logstash-core/lib/logstash/runner.rb
@@ -267,7 +267,7 @@ class LogStash::Runner < Clamp::StrictCommand
          I18n.t("logstash.runner.flag.event_api.tags.illegal"),
          :default => LogStash::SETTINGS.get_default("event_api.tags.illegal"),
          :attribute_name => "event_api.tags.illegal", :passthrough => true,
-         :deprecated_msg => I18n.t("logstash.runner.tags-illegal-deprecated")
+         :obsoleted_version => "9"
 
   # We configure the registry and load any plugin that can register hooks
   # with logstash, this needs to be done before any operation.
diff --git a/logstash-core/locales/en.yml b/logstash-core/locales/en.yml
index ac2319554a9..2521a68255d 100644
--- a/logstash-core/locales/en.yml
+++ b/logstash-core/locales/en.yml
@@ -139,8 +139,6 @@ en:
       configtest-flag-information: |-
         You may be interested in the '--configtest' flag which you can use to validate
         logstash's configuration before you choose to restart a running system.
-      tags-illegal-deprecated: >-
-        The flag '--event_api.tags.illegal' is deprecated and will be removed in version 9.
       tags-illegal-warning: >-
         Setting `event_api.tags.illegal` to `warn` allows illegal values in the reserved `tags` field, which may crash pipeline unexpectedly.
         This flag is deprecated and will be removed in version 9.
diff --git a/logstash-core/spec/logstash/runner_spec.rb b/logstash-core/spec/logstash/runner_spec.rb
index cb07fde6d51..0408e9de173 100644
--- a/logstash-core/spec/logstash/runner_spec.rb
+++ b/logstash-core/spec/logstash/runner_spec.rb
@@ -384,7 +384,7 @@
       let(:runner_deprecation_logger_stub) { double("DeprecationLogger(Runner)").as_null_object }
       let(:args) { ["--event_api.tags.illegal", "warn", "-e", pipeline_string] }
       before(:each) { allow(runner).to receive(:deprecation_logger).and_return(runner_deprecation_logger_stub) }
-      DEPRECATED_MSG="The flag '--event_api.tags.illegal' is deprecated and will be removed in version 9"
+      DEPRECATED_MSG="The flag [\"--event_api.tags.illegal\"] has been deprecated and will be removed in version 9"
 
       it "gives deprecation message when setting to `warn`" do
         expect(runner_deprecation_logger_stub).to receive(:deprecated)