diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f2a69e..1ba1d4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # attr_encrypted
 
+## Unreleased
+
+* Reduce gem size by excluding test files
+
 ## 4.2.0
 
 * Changed: Set minimum Ruby version as 2.7.
diff --git a/attr_encrypted.gemspec b/attr_encrypted.gemspec
index 699b070..1741609 100644
--- a/attr_encrypted.gemspec
+++ b/attr_encrypted.gemspec
@@ -21,8 +21,11 @@ Gem::Specification.new do |s|
 
   s.require_paths = ['lib']
 
-  s.files      = `git ls-files`.split("\n")
-  s.test_files = `git ls-files -- test/*`.split("\n")
+  s.files = Dir.glob('lib/**/*') + [
+    'CHANGELOG.md',
+    'MIT-LICENSE',
+    'README.md'
+  ]
 
   s.required_ruby_version = '>= 2.7.0'