diff --git a/.ameba.yml b/.ameba.yml
new file mode 100644
index 0000000..862ab58
--- /dev/null
+++ b/.ameba.yml
@@ -0,0 +1,2 @@
+Performance/MinMaxAfterMap:
+  Enabled: false
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4d0745c..ba405fa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,8 +9,13 @@ jobs:
   test:
     strategy:
       fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            lint: true
+          - os: windows-latest
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
 
     env:
       TERM: xterm-256color
@@ -23,12 +28,14 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Check formatting
+        if: ${{ matrix.lint  }}
         run: crystal tool format --check
 
       - name: Install dependencies
         run: shards install
 
       - name: Run linter
+        if: ${{ matrix.lint  }}
         run: ./bin/ameba
 
       - name: Setup environment
diff --git a/examples/sam.cr b/examples/sam.cr
index 4e6df6d..66ac1b7 100644
--- a/examples/sam.cr
+++ b/examples/sam.cr
@@ -87,16 +87,16 @@ end
 namespace "db" do
   namespace "schema" do
     desc "just test"
-    task "load" do |t, args|
+    task "load" do |task, args|
       puts args["f1"]
-      t.invoke("1")
-      t.invoke("schema:1")
-      t.invoke("db:migrate")
-      t.invoke("db:db:migrate")
-      t.invoke("db:ping")
-      t.invoke("din:dong")
+      task.invoke("1")
+      task.invoke("schema:1")
+      task.invoke("db:migrate")
+      task.invoke("db:db:migrate")
+      task.invoke("db:ping")
+      task.invoke("din:dong")
       puts "------"
-      t.invoke("2", {"f2" => 1})
+      task.invoke("2", {"f2" => 1})
     end
 
     desc "1"
diff --git a/shard.yml b/shard.yml
index 48fe251..2eb71b1 100644
--- a/shard.yml
+++ b/shard.yml
@@ -11,7 +11,7 @@ license: MIT
 development_dependencies:
   ameba:
     github: crystal-ameba/ameba
-    version: "= 1.4.3"
+    version: "= 1.6.1"
 
 scripts:
   postinstall: "false | [ -f ../../sam.cr ]  && true || cp -i examples/sam.template ../../sam.cr 2>/dev/null"
diff --git a/spec/sam_spec.cr b/spec/sam_spec.cr
index e1fafe9..1bcb07e 100644
--- a/spec/sam_spec.cr
+++ b/spec/sam_spec.cr
@@ -1,5 +1,7 @@
 require "./spec_helper"
 
+executable = "crystal #{File.join("examples", "sam.cr")}"
+
 describe Sam do
   describe ".namespace" do
     pending "add" do
@@ -27,7 +29,7 @@ describe Sam do
 
   describe ".help" do
     it "with multiple tasks" do
-      res = execute("crystal examples/sam.cr", ["db:with_argument", "f1=a", "@", "db:ping"])
+      res = execute(executable, ["db:with_argument", "f1=a", "@", "db:ping"])
       res[1].should eq(<<-TEXT)
       a
       ping
@@ -44,7 +46,7 @@ describe Sam do
     end
 
     it "without a specified task and without a default task defined" do
-      res = execute("crystal examples/sam.cr", %w[])
+      res = execute(executable, %w[])
       res[1].should eq(<<-TEXT)
       Hm, nothing to do...
 
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
index 57e5e5b..4d5fe66 100644
--- a/spec/spec_helper.cr
+++ b/spec/spec_helper.cr
@@ -25,7 +25,12 @@ end
 def execute(command, options)
   io = IO::Memory.new
 
-  status = Process.run("#{command} \"${@}\"", options, shell: true, output: io, error: io).exit_status
+  status =
+    {% if flag?(:win32) %}
+      Process.run("#{command} \"${@}\"", options, output: io, error: io)
+    {% else %}
+      Process.run("#{command} \"${@}\"", options, shell: true, output: io, error: io)
+    {% end %}.exit_status
   {status, io.to_s}
 end
 
@@ -40,16 +45,16 @@ end
 
 namespace "db" do
   namespace "schema" do
-    task "load" do |t, args|
+    task "load" do |task, args|
       puts args["f1"]
-      t.invoke("1")
-      t.invoke("schema:1")
-      t.invoke("db:migrate")
-      t.invoke("db:db:migrate")
-      t.invoke("db:ping")
-      t.invoke("din:dong")
-      t.invoke("schema")
-      Container.add(t.path)
+      task.invoke("1")
+      task.invoke("schema:1")
+      task.invoke("db:migrate")
+      task.invoke("db:db:migrate")
+      task.invoke("db:ping")
+      task.invoke("din:dong")
+      task.invoke("schema")
+      Container.add(task.path)
     end
 
     task "1" do
@@ -58,9 +63,9 @@ namespace "db" do
     end
   end
 
-  task "with_argument" do |t, args|
+  task "with_argument" do |task, args|
     puts args["f1"]
-    Container.add(t.path)
+    Container.add(task.path)
   end
 
   task "schema" do
diff --git a/spec/task_spec.cr b/spec/task_spec.cr
index 44a742a..2449dd2 100644
--- a/spec/task_spec.cr
+++ b/spec/task_spec.cr
@@ -116,7 +116,7 @@ describe Sam::Task do
     it "accepts arg object" do
       count = 0
       namespace.task("t1") { |_, args| count += args["count"].as(Int32) }
-      namespace.task("t2") { |t, args| t.invoke("t1", args) }.call(Sam::Args.new({"count" => 2}))
+      namespace.task("t2") { |task, args| task.invoke("t1", args) }.call(Sam::Args.new({"count" => 2}))
       count.should eq(2)
     end
 
@@ -160,7 +160,7 @@ describe Sam::Task do
     it "accepts arg object" do
       count = 0
       namespace.task("t1") { |_, args| count += args["count"].as(Int32) }
-      namespace.task("t2") { |t, args| t.execute("t1", args) }.call(Sam::Args.new({"count" => 2}))
+      namespace.task("t2") { |task, args| task.execute("t1", args) }.call(Sam::Args.new({"count" => 2}))
       count.should eq(2)
     end