diff --git a/lib/denko/motor/servo.rb b/lib/denko/motor/servo.rb
index 837e3df..9a9b1e6 100644
--- a/lib/denko/motor/servo.rb
+++ b/lib/denko/motor/servo.rb
@@ -5,6 +5,7 @@ class Servo
       include Behaviors::Threaded
 
       def after_initialize(options={})
+        options[:mode] = :output_pwm
         super(options)
         @min = options[:min] || 544
         @max = options[:max] || 2400
diff --git a/lib/denko/pulse_io/buzzer.rb b/lib/denko/pulse_io/buzzer.rb
index e57c391..88fd66b 100644
--- a/lib/denko/pulse_io/buzzer.rb
+++ b/lib/denko/pulse_io/buzzer.rb
@@ -1,6 +1,11 @@
 module Denko
   module PulseIO
     class Buzzer < PWMOutput
+      def initialize_pins(options={})
+        options[:mode] = :output_pwm
+        super(options)
+      end
+
       def after_initialize(options={})
         low
       end
diff --git a/lib/denko/pulse_io/ir_transmitter.rb b/lib/denko/pulse_io/ir_transmitter.rb
index 86677bd..ca0d81b 100644
--- a/lib/denko/pulse_io/ir_transmitter.rb
+++ b/lib/denko/pulse_io/ir_transmitter.rb
@@ -3,6 +3,11 @@ module PulseIO
     class IRTransmitter
       include Behaviors::OutputPin
 
+      def initialize_pins(options={})
+        options[:mode] = :output_pwm
+        super(options)
+      end
+
       def emit(pulses=[], frequency: 38)
         if pulses.length > 256 || pulses.length < 1
           raise ArgumentError, 'wrong number of IR pulses (expected 1 to 256)'