diff --git a/config/puma.rb b/config/puma.rb
index 683d0ba0..7b49289f 100644
--- a/config/puma.rb
+++ b/config/puma.rb
@@ -1,28 +1,32 @@
+# frozen_string_literal: true
+
+require 'prometheus_exporter/instrumentation'
+
 # Puma can serve each request in a thread from an internal thread pool.
 # The `threads` method setting takes two numbers: a minimum and maximum.
 # Any libraries that use thread pools should be configured to match
 # the maximum value specified for Puma. Default is set to 5 threads for minimum
 # and maximum; this matches the default thread size of Active Record.
 #
-max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
-min_threads_count = ENV.fetch("RAILS_MIN_THREADS") { max_threads_count }
+max_threads_count = ENV.fetch('RAILS_MAX_THREADS') { 5 }
+min_threads_count = ENV.fetch('RAILS_MIN_THREADS') { max_threads_count }
 threads min_threads_count, max_threads_count
 
 # Specifies the `worker_timeout` threshold that Puma will use to wait before
 # terminating a worker in development environments.
 #
-worker_timeout 3600 if ENV.fetch("RAILS_ENV", "development") == "development"
+worker_timeout 3600 if ENV.fetch('RAILS_ENV', 'development') == 'development'
 
 # Specifies the `port` that Puma will listen on to receive requests; default is 3000.
 #
-port ENV.fetch("PORT") { 3000 }
+port ENV.fetch('PORT') { 3000 }
 
 # Specifies the `environment` that Puma will run in.
 #
-environment ENV.fetch("RAILS_ENV") { "development" }
+environment ENV.fetch('RAILS_ENV') { 'development' }
 
 # Specifies the `pidfile` that Puma will use.
-pidfile ENV.fetch("PIDFILE") { "tmp/pids/server.pid" }
+pidfile ENV.fetch('PIDFILE') { 'tmp/pids/server.pid' }
 
 # Specifies the number of `workers` to boot in clustered mode.
 # Workers are forked web server processes. If using threads and workers together
@@ -42,8 +46,7 @@ pidfile ENV.fetch("PIDFILE") { "tmp/pids/server.pid" }
 # Allow puma to be restarted by `bin/rails restart` command.
 plugin :tmp_restart
 
-# Promethues exporter
-after_worker_boot do
-  require 'prometheus_exporter/instrumentation'
-  PrometheusExporter::Instrumentation::Process.start(type:"web")
-end
+# Prometheus exporter
+#
+# optional check, avoids spinning up and down threads per worker
+PrometheusExporter::Instrumentation::Puma.start unless PrometheusExporter::Instrumentation::Puma.started?