diff --git a/lib/uh/wm/dispatcher.rb b/lib/uh/wm/dispatcher.rb
index 697e5af..d8ada3c 100644
--- a/lib/uh/wm/dispatcher.rb
+++ b/lib/uh/wm/dispatcher.rb
@@ -3,21 +3,20 @@ module Uh
     class Dispatcher
       attr_reader :hooks
 
-      def initialize hooks = Hash.new
-        @hooks = hooks
+      def initialize
+        @hooks = Hash.new { |h, k| h[k] = [] }
       end
 
       def [] *key
-        @hooks[translate_key key] or []
+        @hooks[translate_key key]
       end
 
       def on *key, &block
-        @hooks[translate_key key] ||= []
         @hooks[translate_key key] << block
       end
 
       def emit *key
-        @hooks[translate_key key].tap { |o| o.each { |e| e.call } if o }
+        @hooks[translate_key key].each { |e| e.call }
       end
 
 
diff --git a/spec/uh/wm/dispatcher_spec.rb b/spec/uh/wm/dispatcher_spec.rb
index bd06d11..3399351 100644
--- a/spec/uh/wm/dispatcher_spec.rb
+++ b/spec/uh/wm/dispatcher_spec.rb
@@ -1,12 +1,11 @@
 module Uh
   module WM
     RSpec.describe Dispatcher do
-      let(:hooks)           { {} }
-      subject(:dispatcher)  { described_class.new hooks }
+      subject(:dispatcher)  { described_class.new }
 
       describe '#[]' do
         context 'when given key for existing hook' do
-          let(:hooks) { { hook_key: [:hook] } }
+          before { dispatcher.hooks[:hook_key] = [:hook] }
 
           it 'returns registered hooks for this key' do
             expect(dispatcher[:hook_key]).to eq [:hook]
@@ -14,7 +13,7 @@ module Uh
         end
 
         context 'when given multiple keys for existing hook' do
-          let(:hooks) { { %i[hook key] => [:hook] } }
+          before { dispatcher.hooks[%i[hook key]] = [:hook] }
 
           it 'returns registered hooks for this key' do
             expect(dispatcher[:hook, :key]).to eq [:hook]