diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 4801952..34f382a 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -1,8 +1,14 @@
-name: CI
+name: CI on Ubuntu
 
 on:
-- push
-- pull_request
+  push:
+    branches:
+    - master
+  pull_request:
+    types:
+    - opened
+    - synchronize
+    - reopened
 
 jobs:
   test:
@@ -43,8 +49,6 @@ jobs:
         sudo pip3 install wheel
         sudo pip3 install -r ci/requirements.txt
 
-    - run: gem install bundler
-
     - run: bundle install --jobs 4 --retry 3
 
     - name: Run tests
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
new file mode 100644
index 0000000..f83bf14
--- /dev/null
+++ b/.github/workflows/windows.yml
@@ -0,0 +1,71 @@
+name: CI on Windows
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    types:
+    - opened
+    - synchronize
+    - reopened
+
+jobs:
+  test:
+    name: Test
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+        - windows-latest
+        ruby:
+        - "3.0"
+        - 2.7
+        - 2.6
+        - 2.5
+        - 2.4
+        - 2.3
+        - mswin
+        - mingw
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 1
+
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+
+    - uses: actions/cache@v2
+      with:
+        path: C:\vcpkg\downloads
+        key: ${{ runner.os }}-vcpkg-downloads-${{ matrix.os }}-${{ github.sha }}
+        restore-keys: |
+          ${{ runner.os }}-vcpkg-downloads-${{ matrix.os }}-
+          ${{ runner.os }}-vcpkg-downloads-
+
+    - name: Install requirements on vcpkg
+      run: |
+        vcpkg --triplet x64-windows install zeromq czmq libffi
+        dir C:/vcpkg/installed/x64-windows/bin
+        cp C:/vcpkg/installed/x64-windows/bin/libzmq-mt-4_3_3.dll C:/vcpkg/installed/x64-windows/bin/libzmq.dll
+
+    - name: Add vcpkg bindir in PATH
+      run: echo "C:/vcpkg/installed/x64-windows/bin" >> $GITHUB_PATH
+      shell: bash
+
+    - run: pip3 install -r ci/requirements.txt
+
+    - run: bundle install --jobs 4 --retry 3 --without "pycall cztop"
+
+    - name: Run test with ffi-rzmq
+      run: bundle exec rake test TESTOPTS=-v
+      env:
+        IRUBY_TEST_SESSION_ADAPTER_NAME: ffi-rzmq
+
+    - run: rake build
+
+    - run: gem install pkg/*.gem
diff --git a/Gemfile b/Gemfile
index b76e937..2be258d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,6 +12,10 @@ group :plot do
   gem 'rubyvis'
 end
 
-group :test do
+group :pycall do
+  gem 'pycall'
+end
+
+group :cztop do
   gem 'cztop'
 end
diff --git a/iruby.gemspec b/iruby.gemspec
index 9fee5a0..fb1e3d8 100644
--- a/iruby.gemspec
+++ b/iruby.gemspec
@@ -23,7 +23,6 @@ Gem::Specification.new do |s|
   s.add_dependency 'mimemagic', '~> 0.3'
   s.add_dependency 'multi_json', '~> 1.11'
 
-  s.add_development_dependency 'pycall', '>= 1.2.1'
   s.add_development_dependency 'rake'
   s.add_development_dependency 'test-unit'
   s.add_development_dependency 'test-unit-rr'
diff --git a/test/helper.rb b/test/helper.rb
index e62b854..5ee8bc0 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -72,7 +72,7 @@ def windows_only
     end
 
     def apple_only
-      omit('apple only test') unless windows?
+      omit('apple only test') unless apple?
     end
 
     def unix_only