diff --git a/.travis.yml b/.travis.yml
index 25320325..1cb32097 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,20 +3,29 @@ language:
 
 rvm:
   - '2.0'
-  - '2.1'
-  - '2.2'
-  - '2.3.0'
+  - '2.3.1'
 
 matrix:
   fast_finish:
     true
 
-install: true
-
 before_install:
-  - sudo apt-get update -qq
-  - sudo apt-get install ruby gcc ruby-dev rake make -y
+  - sudo apt-get install -y lcov
+
+cache: bundler
+
+
+before_script:
+  - bundle exec rake compile -- --enable-gcov
 
 script:
-  - gem build numo-narray.gemspec
-  - gem install numo-narray-0.9.0.3.gem
+  - bundle exec rake spec
+  - bundle exec gem build numo-narray.gemspec
+  - bundle exec gem install numo-narray-0.9.0.3.gem
+
+after_success:
+  - cd ${TRAVIS_BUILD_DIR}
+  - lcov --directory tmp --capture --output-file coverage.info # capture coverage info
+  - lcov --remove coverage.info '*.h' --output-file coverage.info # remove *.h coverages
+  - lcov --list coverage.info # debug before upload
+  - bundle exec coveralls-lcov --repo-token ${COVERALLS_TOKEN} coverage.info # uploads to coveralls
\ No newline at end of file
diff --git a/Rakefile b/Rakefile
index 2b5ca481..4a3884e1 100644
--- a/Rakefile
+++ b/Rakefile
@@ -3,6 +3,8 @@ begin
 require "rake/extensiontask"
 require "rake_compiler_dock"
 require "shellwords"
+require "rspec/core/rake_task"
+
 
 spec = Bundler::GemHelper.gemspec
 
@@ -12,6 +14,9 @@ Rake::ExtensionTask.new("numo/narray", spec) do |ext|
   ext.cross_platform = cross_platforms
 end
 
+RSpec::Core::RakeTask.new("spec")
+Rake::Task[:spec].prerequisites << :compile
+
 pkg_dir = "pkg"
 windows_gem_paths = cross_platforms.collect do |platform|
   File.join(pkg_dir, "#{spec.full_name}-#{platform}.gem")
diff --git a/ext/numo/narray/depend.erb b/ext/numo/narray/depend.erb
index dd1c205a..7ab97c42 100644
--- a/ext/numo/narray/depend.erb
+++ b/ext/numo/narray/depend.erb
@@ -32,4 +32,4 @@ DEPENDS = $(C_TMPL) $(DTYPE) <%= __dir__ %>/gen/*.rb
 
 src : <%= type_c.join(" ") %>
 
-CLEANOBJS = *.o */*.o *.bak types/*.c
+CLEANOBJS = *.o */*.o *.bak types/*.c *.gcno *.gcda *.gcov types/*.gcno types/*.gcda types/*.gcov
diff --git a/ext/numo/narray/extconf.rb b/ext/numo/narray/extconf.rb
index db2ca207..bfb0e0cb 100644
--- a/ext/numo/narray/extconf.rb
+++ b/ext/numo/narray/extconf.rb
@@ -20,6 +20,11 @@
   $INSTALLFILES << ['libnarray.a', '$(archdir)']
 end
 
+if enable_config("gcov")
+  $CFLAGS += " -coverage"
+  $LDFLAGS += " -coverage"
+end
+
 srcs = %w(
 narray
 array
diff --git a/numo-narray.gemspec b/numo-narray.gemspec
index 2c1eaec1..01ce2f1e 100644
--- a/numo-narray.gemspec
+++ b/numo-narray.gemspec
@@ -32,4 +32,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rspec", "~> 3"
   spec.add_development_dependency "rake-compiler", ">= 1.0.1"
   spec.add_development_dependency "rake-compiler-dock"
+  spec.add_development_dependency "coveralls-lcov"
 end
diff --git a/spec/bit_spec.rb b/spec/bit_spec.rb
index bc368635..e69ffdc7 100644
--- a/spec/bit_spec.rb
+++ b/spec/bit_spec.rb
@@ -1,4 +1,4 @@
-require File.join(File.dirname(__FILE__), "../ext/numo/narray/narray")
+require_relative '../lib/numo/narray.so'
 #Numo::NArray.debug = true
 
 RSpec.configure do |config|
diff --git a/spec/narray_spec.rb b/spec/narray_spec.rb
index 93e70480..f569baaa 100644
--- a/spec/narray_spec.rb
+++ b/spec/narray_spec.rb
@@ -1,4 +1,4 @@
-require File.join(File.dirname(__FILE__), "../ext/numo/narray/narray")
+require_relative "../lib/numo/narray.so"
 #Numo::NArray.debug = true
 
 RSpec.configure do |config|