diff --git a/lib/govuk_app_config/govuk_puma.rb b/lib/govuk_app_config/govuk_puma.rb
index fb973a4c..11af0acb 100644
--- a/lib/govuk_app_config/govuk_puma.rb
+++ b/lib/govuk_app_config/govuk_puma.rb
@@ -6,7 +6,7 @@ def self.configure(config)
 
     # Specifies the `environment` that Puma will run in.
     #
-    config.environment ENV.fetch("RAILS_ENV") { "development" }
+    config.environment ENV.fetch("RAILS_ENV", "development")
 
     if ENV["GOVUK_APP_LOGROOT"]
       config.stdout_redirect "#{ENV['GOVUK_APP_LOGROOT']}/app.out.log" "#{ENV['GOVUK_APP_LOGROOT']}/app.err.log"
@@ -25,7 +25,7 @@ def self.configure(config)
     # 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 }
+    min_threads_count = ENV.fetch("RAILS_MIN_THREADS", max_threads_count)
     config.threads min_threads_count, max_threads_count
 
     # Specifies the number of `workers` to boot in clustered mode.