diff --git a/bin/rails b/bin/rails
index 595d7184197..eedb72185b1 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-if !ENV["RAILS_ENV"] && (ARGV[0] == "s" || ARGV[0] == "server")
+if !ENV["RAILS_ENV"] && (ARGV[0] == "s" || ARGV[0] == "server") && Process.respond_to?(:fork)
   ENV["UNICORN_PORT"] ||= "3000"
 
   if ARGV[1] == "-p" && (port = ARGV[2].to_i) > 0
diff --git a/config/initializers/006-mini_profiler.rb b/config/initializers/006-mini_profiler.rb
index 2f80ebffc16..297ccdfbdee 100644
--- a/config/initializers/006-mini_profiler.rb
+++ b/config/initializers/006-mini_profiler.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 # If Mini Profiler is included via gem
-if Rails.configuration.respond_to?(:load_mini_profiler) && Rails.configuration.load_mini_profiler
+if Rails.configuration.respond_to?(:load_mini_profiler) && Rails.configuration.load_mini_profiler && RUBY_ENGINE == "ruby"
   require 'rack-mini-profiler'
   require 'stackprof'
 
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 2c408aa03cd..5f4fba08c82 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -13,7 +13,7 @@ if ENV['COVERAGE']
 end
 
 require 'rubygems'
-require 'rbtrace'
+require 'rbtrace' if RUBY_ENGINE == "ruby"
 require 'pry'
 require 'pry-byebug'
 require 'pry-rails'