diff --git a/README.md b/README.md
index baf3091..436a421 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ options:
     -f, --run-control PATH           specify alternate run control file
     -r, --require PATH               require ruby feature
     -l, --layout LAYOUT              specify layout
+    -w, --worker WORKER              specify worker
 ```
 
 
diff --git a/features/cli/worker.feature b/features/cli/worker.feature
new file mode 100644
index 0000000..94162e7
--- /dev/null
+++ b/features/cli/worker.feature
@@ -0,0 +1,9 @@
+Feature: worker CLI option
+
+  Scenario: uses the blocking worker when `block' is given
+    When I run uhwm with option -v -w block
+    Then the output must match /work.+event.+block/i
+
+  Scenario: uses the multiplexing worker when `mux' is given
+    When I run uhwm with option -v -w mux
+    Then the output must match /work.+event.+mux/i
diff --git a/features/steps/output_steps.rb b/features/steps/output_steps.rb
index 73cd67f..875bf1a 100644
--- a/features/steps/output_steps.rb
+++ b/features/steps/output_steps.rb
@@ -9,6 +9,7 @@ options:
     -f, --run-control PATH           specify alternate run control file
     -r, --require PATH               require ruby feature
     -l, --layout LAYOUT              specify layout
+    -w, --worker WORKER              specify worker
   eoh
 end
 
diff --git a/lib/uh/wm/cli.rb b/lib/uh/wm/cli.rb
index 8853582..12631d9 100644
--- a/lib/uh/wm/cli.rb
+++ b/lib/uh/wm/cli.rb
@@ -77,6 +77,11 @@ module Uh
           opts.on '-l', '--layout LAYOUT', 'specify layout' do |layout|
             @env.layout_class = self.class.const_get layout.to_sym
           end
+
+          opts.on '-w', Workers.types, '--worker WORKER',
+            'specify worker' do |worker|
+            @env.worker = worker.to_sym
+          end
         end
       end
     end
diff --git a/lib/uh/wm/runner.rb b/lib/uh/wm/runner.rb
index 8bee78b..582869a 100644
--- a/lib/uh/wm/runner.rb
+++ b/lib/uh/wm/runner.rb
@@ -73,7 +73,9 @@ module Uh
       end
 
       def run_until &block
-        manager.handle_pending_events until block.call
+        worker.watch @manager
+        @env.log "Working events with `#{worker.class}'"
+        worker.work_events until block.call
       end
 
       def terminate
diff --git a/spec/uh/wm/cli_spec.rb b/spec/uh/wm/cli_spec.rb
index 6bcf551..027546c 100644
--- a/spec/uh/wm/cli_spec.rb
+++ b/spec/uh/wm/cli_spec.rb
@@ -176,6 +176,15 @@ module Uh
           end
         end
 
+        context 'with worker option' do
+          let(:arguments) { %w[-w mux] }
+
+          it 'assigns the worker type in the env' do
+            cli.parse_arguments!
+            expect(cli.env.worker).to eq :mux
+          end
+        end
+
         context 'with invalid option' do
           let(:arguments) { %w[--unknown-option] }
 
diff --git a/spec/uh/wm/runner_spec.rb b/spec/uh/wm/runner_spec.rb
index 863abba..bda4bef 100644
--- a/spec/uh/wm/runner_spec.rb
+++ b/spec/uh/wm/runner_spec.rb
@@ -144,10 +144,15 @@ module Uh
       end
 
       describe '#run_until' do
-        it 'tells the manager to handle events until given block is true' do
+        it 'tells the worker to watch the manager' do
+          expect(runner.worker).to receive(:watch).with runner.manager
+          runner.run_until { true }
+        end
+
+        it 'tells the worker to work events until given block is true' do
           block = proc { }
           allow(block).to receive(:call).and_return(false, false, false, true)
-          expect(runner.manager).to receive(:handle_pending_events).exactly(3).times
+          expect(runner.worker).to receive(:work_events).exactly(3).times
           runner.run_until &block
         end
       end