diff --git a/.gitignore b/.gitignore
index 0124c1492..5864c4dd1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -41,6 +41,7 @@
 *.so
 *.so.*
 *.dylib
+*.bundle
 
 # Executables
 *.exe
@@ -64,3 +65,6 @@ modules.order
 Module.symvers
 Mkfile.old
 dkms.conf
+
+# Temporary files
+tmp/*
diff --git a/Makefile b/Makefile
index 2dad3d7f0..3ee73c116 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ test_sources = $(wildcard test/*.c)
 test_objects = $(test_sources:.c=.o)
 non_main_objects = $(filter-out src/main.o, $(objects))
 
-soext ?= $(shell ruby -e 'puts RbConfig::CONFIG["SOEXT"]')
+soext ?= $(shell ruby -e 'puts RbConfig::CONFIG["DLEXT"]')
 lib_name = lib$(exec).$(soext)
 ruby_extension = ext/erbx/$(lib_name)
 
@@ -47,4 +47,4 @@ test: $(test_objects) $(non_main_objects)
 
 clean:
 	rm -f $(exec) $(test_exec) $(lib_name) $(ruby_extension)
-	rm -f src/*.o test/*.o
+	rm -rf src/*.o test/*.o lib/erbx/*.bundle tmp
diff --git a/Rakefile b/Rakefile
index b8984c84a..d57104dec 100644
--- a/Rakefile
+++ b/Rakefile
@@ -17,23 +17,24 @@ Rake::TestTask.new(:test) do |t|
 end
 
 Rake::Task[:compile].enhance do
-   IO.popen("make") do |output|
-     output.each_line do |line|
-       puts "#{line}"
-     end
-   end
+  IO.popen("make") do |output|
+    output.each_line do |line|
+      puts "#{line}"
+    end
+  end
+
+  if $?.exitstatus != 0
+    raise "src/* could not be compiled #{$?.exitstatus}"
+  end
+end
 
-   if $?.exitstatus != 0
-     raise "src/* could not be compiled #{$?.exitstatus}"
-   end
- end
 
- Rake::Task[:clean].enhance do
-   IO.popen("make clean") do |output|
-     output.each_line do |line|
-       puts "#{line}"
-     end
-   end
- end
+Rake::Task[:clean].enhance do
+  IO.popen("make clean") do |output|
+    output.each_line do |line|
+      puts "#{line}"
+    end
+  end
+end
 
- task default: [:compile, :test]
\ No newline at end of file
+task default: [:compile, :test]
diff --git a/erbx.gemspec b/erbx.gemspec
index 21bdda211..cd77bd2f6 100644
--- a/erbx.gemspec
+++ b/erbx.gemspec
@@ -13,11 +13,14 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = ">= 3.0.0"
 
   spec.require_paths = ["lib"]
-  spec.files = [
-    "ext/erbx/extension.c",
-    "lib/erbx.rb",
-    # "lib/erbx/version.rb"
-  ]
+
+  gemspec = File.basename(__FILE__)
+  spec.files = IO.popen(%w[git ls-files -z], chdir: __dir__, err: IO::NULL) do |ls|
+    ls.readlines("\x0", chomp: true).reject do |f|
+      (f == gemspec) ||
+        f.start_with?(*%w[bin/ test/ spec/ features/ .git .github appveyor Gemfile])
+    end
+  end
 
   spec.extensions = ["ext/erbx/extconf.rb"]
   spec.metadata["allowed_push_host"] = "https://rubygems.org"
diff --git a/ext/erbx/extconf.rb b/ext/erbx/extconf.rb
index a7b2ea32a..2d512f9c4 100644
--- a/ext/erbx/extconf.rb
+++ b/ext/erbx/extconf.rb
@@ -9,16 +9,5 @@
   abort "#{extension_name}.h can't be found"
 end
 
-# expected_functions = [
-#   "erbx_lex",
-#   "erbx_lex_file",
-# ]
-#
-# expected_functions.each do |expected_function|
-#   unless find_library(extension_name, expected_function)
-#     abort "lib#{extension_name}.so can't be found or #{expected_function}() not defined in it"
-#   end
-# end
-
 create_header
 create_makefile("#{extension_name}/#{extension_name}")
diff --git a/lib/erbx/liberbx.rb b/lib/erbx/liberbx.rb
index 692bf18de..51f330837 100644
--- a/lib/erbx/liberbx.rb
+++ b/lib/erbx/liberbx.rb
@@ -8,7 +8,7 @@ module LibERBX
     extend FFI::Library
 
     def self.library_extension
-      RbConfig::CONFIG["SOEXT"]
+      RbConfig::CONFIG["DLEXT"]
     end
 
     def self.library_name