diff --git a/exe/scelint b/exe/scelint
index fff9e89..aff48af 100755
--- a/exe/scelint
+++ b/exe/scelint
@@ -3,4 +3,4 @@
 
 require 'scelint/cli'
 
-Scelint::CLI.start(['lint'] + ARGV)
+Scelint::CLI.start
diff --git a/lib/scelint/cli.rb b/lib/scelint/cli.rb
index d62ccc6..e38db83 100644
--- a/lib/scelint/cli.rb
+++ b/lib/scelint/cli.rb
@@ -6,6 +6,20 @@
 
 # SCELint CLI
 class Scelint::CLI < Thor
+  def self.exit_on_failure?
+    true
+  end
+
+  # When the first argument is not a known subcommand or an option flag,
+  # treat all arguments as paths for the default `lint` command.
+  def self.start(given_args = ARGV, config = {})
+    args = given_args
+    if args.first && !args.first.start_with?('-') && !all_commands.key?(args.first)
+      args = ['lint'] + args
+    end
+    super(args, config)
+  end
+
   class_option :quiet, type: :boolean, aliases: '-q', default: false
   class_option :verbose, type: :boolean, aliases: '-v', default: false
   class_option :debug, type: :boolean, aliases: '-d', default: false
diff --git a/spec/unit/scelint/cli_spec.rb b/spec/unit/scelint/cli_spec.rb
new file mode 100644
index 0000000..6ed41d8
--- /dev/null
+++ b/spec/unit/scelint/cli_spec.rb
@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'scelint/cli'
+
+RSpec.describe Scelint::CLI do
+  let(:fixtures_dir) { File.expand_path('../../fixtures/modules', __dir__) }
+  let(:clean_module_path) { File.join(fixtures_dir, 'test_module_01') }
+  let(:warning_module_path) { File.join(fixtures_dir, 'test_module_04') }
+
+  # Runs the CLI via .start (as a user would invoke from the command line),
+  # captures the SystemExit status, and suppresses stdout noise from the logger.
+  def run_cli(args)
+    Scelint::CLI.start(args)
+  rescue SystemExit => e
+    e.status
+  end
+
+  before(:each) do
+    # Silence logger output to keep spec output clean.
+    allow(Logger).to receive(:new).and_return(Logger.new(File::NULL))
+  end
+
+  describe 'invocation without an explicit subcommand' do
+    context 'with a path argument' do
+      it 'lints the given path' do
+        expect(run_cli([clean_module_path])).to eq(0)
+      end
+
+      it 'lints multiple path arguments' do
+        expect(run_cli([clean_module_path, warning_module_path])).to eq(0)
+      end
+    end
+
+    context 'with no path argument' do
+      it 'defaults to linting the current directory' do
+        # The repo root has no SCE data, so lint finds no files and exits 0
+        expect(run_cli([])).to eq(0)
+      end
+    end
+  end
+
+  describe 'explicit lint subcommand' do
+    it 'lints the given path' do
+      expect(run_cli(['lint', clean_module_path])).to eq(0)
+    end
+
+    it 'defaults to current directory when no path is given' do
+      expect(run_cli(['lint'])).to eq(0)
+    end
+  end
+
+  describe 'exit codes' do
+    context 'when there are no errors and no warnings' do
+      it 'exits 0' do
+        expect(run_cli([clean_module_path])).to eq(0)
+      end
+    end
+
+    context 'when there are warnings but no errors' do
+      it 'exits 0 without --strict' do
+        expect(run_cli([warning_module_path])).to eq(0)
+      end
+
+      it 'exits 1 with --strict' do
+        expect(run_cli(['--strict', warning_module_path])).to eq(1)
+      end
+    end
+  end
+
+  describe '--quiet flag' do
+    it 'exits 0 on a clean module' do
+      expect(run_cli(['--quiet', clean_module_path])).to eq(0)
+    end
+  end
+
+  describe '--verbose flag' do
+    it 'exits 0 on a clean module' do
+      expect(run_cli(['--verbose', clean_module_path])).to eq(0)
+    end
+  end
+
+  describe '--debug flag' do
+    it 'exits 0 on a clean module' do
+      expect(run_cli(['--debug', clean_module_path])).to eq(0)
+    end
+  end
+end