diff --git a/mutant.gemspec b/mutant.gemspec
index 8ff86b91..79f1f8c2 100644
--- a/mutant.gemspec
+++ b/mutant.gemspec
@@ -13,7 +13,10 @@ Gem::Specification.new do |gem|
   gem.license     = 'MIT'
 
   gem.require_paths    = %w[lib]
-  gem.files            = `git ls-files`.split("\n")
+
+  mutant_rspec_files = `git ls-files -- lib/mutant{-,/}rspec.rb lib/mutant/rspec`.split("\n")
+
+  gem.files            = `git ls-files`.split("\n") - mutant_rspec_files
   gem.test_files       = `git ls-files -- spec/{unit,integration}`.split("\n")
   gem.extra_rdoc_files = %w[TODO LICENSE]
   gem.executables      = %w[mutant]