diff --git a/lib/mutant/killer/forked.rb b/lib/mutant/killer/forked.rb
index e93cd19c..19565ffd 100644
--- a/lib/mutant/killer/forked.rb
+++ b/lib/mutant/killer/forked.rb
@@ -32,7 +32,7 @@ module Mutant
       def run
         pid = fork do
           killer = @killer.new(strategy, mutation)
-          exit(killer.success? ? CLI::EXIT_SUCCESS : CLI::EXIT_FAILURE)
+          exit(killer.killed? ? CLI::EXIT_SUCCESS : CLI::EXIT_FAILURE)
         end
 
         status = Process.wait2(pid).last
diff --git a/lib/mutant/killer/rspec.rb b/lib/mutant/killer/rspec.rb
index a6e202c7..4935dea5 100644
--- a/lib/mutant/killer/rspec.rb
+++ b/lib/mutant/killer/rspec.rb
@@ -20,9 +20,9 @@ module Mutant
         # TODO: replace with real streams from configuration
         require 'stringio'
         null = StringIO.new
-        args = command_line_arguments
+        argv = command_line_arguments
         begin
-          !::RSpec::Core::Runner.run(args, null, null).zero?
+          !::RSpec::Core::Runner.run(argv, null, null).zero?
         rescue StandardError
           true
         end