diff --git a/.ruby-gemset b/.ruby-gemset
deleted file mode 100644
index c4fdec0..0000000
--- a/.ruby-gemset
+++ /dev/null
@@ -1 +0,0 @@
-sidekiq-logstash
\ No newline at end of file
diff --git a/.ruby-version b/.ruby-version
deleted file mode 100644
index 860487c..0000000
--- a/.ruby-version
+++ /dev/null
@@ -1 +0,0 @@
-2.7.1
diff --git a/lib/sidekiq/logstash.rb b/lib/sidekiq/logstash.rb
index be7c831..bf52ddb 100644
--- a/lib/sidekiq/logstash.rb
+++ b/lib/sidekiq/logstash.rb
@@ -22,8 +22,11 @@ def self.configure
     def self.setup(_opts = {})
       # Calls Sidekiq.configure_server to inject logics
       Sidekiq.configure_server do |config|
-        # Remove default Sidekiq error_handler that logs errors
-        config.error_handlers.delete_if { |h| h.is_a?(Sidekiq::ExceptionHandler::Logger) }
+        if defined?(Sidekiq::ExceptionHandler::Logger)
+          # Remove default Sidekiq error_handler that logs errors
+          # NOTE: this only exists up until Sidekiq 6.4.x
+          config.error_handlers.delete_if { |h| h.is_a?(Sidekiq::ExceptionHandler::Logger) }
+        end
 
         # Add logstash support
         config.options[:job_logger] = Sidekiq::LogstashJobLogger
diff --git a/spec/sidekiq/logstash_spec.rb b/spec/sidekiq/logstash_spec.rb
index 9e61d44..45491f8 100644
--- a/spec/sidekiq/logstash_spec.rb
+++ b/spec/sidekiq/logstash_spec.rb
@@ -13,8 +13,8 @@ def process(worker, params = [], encrypt: false)
   let(:buffer) { StringIO.new }
   let(:logger) { Logger.new(buffer) }
   let(:job) { build(:job) }
-  let(:processor_options) { { queues: ['default'] } }
-  let(:processor) { ::Sidekiq::Processor.new(nil, processor_options) }
+  let(:processor_options) { Sidekiq }
+  let(:processor) { ::Sidekiq::Processor.new(processor_options) }
   let(:log_message) { JSON.parse(buffer.string) }
   let(:log_messages) { buffer.string.split("\n").map { |log| JSON.parse(log) } }