diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 000000000..de98947a7
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,38 @@
+name: CI
+on: [push, pull_request]
+jobs:
+  specs:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ ubuntu, macos, windows ]
+        ruby: [ 2.3, 2.4, 2.5, 2.6, 2.7, ruby-head, truffleruby-head ]
+        exclude:
+        - os: windows
+          ruby: truffleruby-head
+        - os: windows
+          ruby: 2.3 # compilation fails
+    runs-on: ${{ matrix.os }}-latest
+    env:
+      MAKE: "make" # to not try to use gmake on Windows
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+
+    - run: brew install automake
+      if: matrix.os == 'macos'
+
+    # Bundler 2 seems to fix installing rubygems-tasks on Ruby < 2.4
+    - run: gem install bundler
+    - run: bundle install
+    - run: bundle exec rake libffi
+    - run: bundle exec rake compile
+
+    - run: bundle exec rake test
+
+    - run: bundle exec rake bench:all
+      if: matrix.ruby != 'truffleruby-head'
+      env:
+        ITER: 10
diff --git a/Rakefile b/Rakefile
index 644eab7b2..91eaba49e 100644
--- a/Rakefile
+++ b/Rakefile
@@ -45,7 +45,7 @@ task :test => [ :spec ]
 
 namespace :bench do
   ITER = ENV['ITER'] ? ENV['ITER'].to_i : 100000
-  bench_files = Dir["bench/bench_*.rb"].reject { |f| f == "bench/bench_helper.rb" }
+  bench_files = Dir["bench/bench_*.rb"].sort.reject { |f| f == "bench/bench_helper.rb" }
   bench_files.each do |bench|
     task File.basename(bench, ".rb")[6..-1] => :compile do
       sh %{#{Gem.ruby} #{bench} #{ITER}}
diff --git a/bench/bench_getlogin.rb b/bench/bench_getlogin.rb
index c5824f4e1..2112cdf40 100644
--- a/bench/bench_getlogin.rb
+++ b/bench/bench_getlogin.rb
@@ -9,8 +9,12 @@ module Posix
     ffi_lib FFI::Library::LIBC
     attach_function :getlogin, [], :string
   end
-  if Posix.getlogin != Etc.getlogin
-    raise ArgumentError, "FFI getlogin returned incorrect value"
+
+  # getlogin(2) might return NULL, in which case Etc.getlogin uses ENV["USER"].
+  # This should not matter for this benchmark, getlogin() is still called.
+  if (Posix.getlogin || ENV["USER"]) != Etc.getlogin
+    raise ArgumentError, "FFI getlogin returned incorrect value: " \
+      "#{Posix.getlogin.inspect} (FFI) vs #{Etc.getlogin.inspect} (Etc)"
   end
 
   puts "Benchmark FFI getlogin(2) performance, #{ITER}x"
@@ -27,4 +31,4 @@ module Posix
       iter.times { Etc.getlogin }
     }
   }
-end
+end unless FFI::Platform.windows?
diff --git a/bench/bench_gettimeofday.rb b/bench/bench_gettimeofday.rb
index 5884d76c3..848fa87d3 100644
--- a/bench/bench_gettimeofday.rb
+++ b/bench/bench_gettimeofday.rb
@@ -50,4 +50,4 @@ class Timeval < FFI::Struct
       iter.times { Time.now }
     }
   }
-end
+end unless FFI::Platform.windows?
diff --git a/bench/bench_getuid.rb b/bench/bench_getuid.rb
index 25aec5398..e82722139 100644
--- a/bench/bench_getuid.rb
+++ b/bench/bench_getuid.rb
@@ -24,4 +24,4 @@ module Posix
       iter.times { Process.uid }
     }
   }
-end
+end unless FFI::Platform.windows?
diff --git a/bench/bench_math.rb b/bench/bench_math.rb
index bea286840..24f4b7be4 100644
--- a/bench/bench_math.rb
+++ b/bench/bench_math.rb
@@ -3,7 +3,7 @@
 module BenchMath
   module FFIMath
     extend FFI::Library
-    ffi_lib 'm'
+    ffi_lib FFI::Platform.windows? ? FFI::Library::LIBC : 'm'
     attach_function :cos, [ :double ], :double
     attach_function :cosf, [ :float ], :float
   end
diff --git a/bench/bench_umask.rb b/bench/bench_umask.rb
index 3692c35c7..1bb547387 100644
--- a/bench/bench_umask.rb
+++ b/bench/bench_umask.rb
@@ -59,4 +59,4 @@ def self.umask(mask = nil)
       ITER.times { NativeFile.umask }
     }
   }
-end
+end unless FFI::Platform.windows?