diff --git a/tikkie-api.gemspec b/tikkie-api.gemspec
index 62633e6..501e174 100644
--- a/tikkie-api.gemspec
+++ b/tikkie-api.gemspec
@@ -16,11 +16,11 @@ Gem::Specification.new do |spec|
 
   spec.metadata['rubygems_mfa_required'] = 'true'
 
-  spec.files = `git ls-files -z`.split("\x0").reject do |f|
-    f.match(%r{^(test|spec|features)/})
-  end
+  # Specify which files should be added to the gem when it is released.
+  spec.files         = Dir['LICENSE.txt', 'README.md', 'lib/**/*']
+
   spec.bindir        = 'exe'
-  spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
+  spec.executables   = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
   spec.required_ruby_version = '>= 3.0.0'