diff --git a/lib/datadog/ci/test_optimisation/skippable_percentage/calculator.rb b/lib/datadog/ci/test_optimisation/skippable_percentage/calculator.rb
index f2aa1b83..bed98b8f 100644
--- a/lib/datadog/ci/test_optimisation/skippable_percentage/calculator.rb
+++ b/lib/datadog/ci/test_optimisation/skippable_percentage/calculator.rb
@@ -66,7 +66,7 @@ def dry_run
             cli_options_array = @rspec_cli_options + ["--dry-run", @spec_path]
 
             rspec_config_options = ::RSpec::Core::ConfigurationOptions.new(cli_options_array)
-            devnull = File.new("/dev/null", "w")
+            devnull = File.new(File::NULL, "w")
             out = @verbose ? $stdout : devnull
             err = @verbose ? $stderr : devnull
 
diff --git a/spec/support/rspec_helpers.rb b/spec/support/rspec_helpers.rb
index 98e0e78d..967e54da 100644
--- a/spec/support/rspec_helpers.rb
+++ b/spec/support/rspec_helpers.rb
@@ -16,6 +16,6 @@ def with_new_rspec_environment
   end
 
   def devnull
-    File.new("/dev/null", "w")
+    File.new(File::NULL, "w")
   end
 end