diff --git a/inc/DynamicPwm.h b/inc/DynamicPwm.h
index dbd66ea..f17d7d4 100644
--- a/inc/DynamicPwm.h
+++ b/inc/DynamicPwm.h
@@ -4,7 +4,6 @@
 #define MICROBIT_DYNAMIC_PWM_H
 
 #define NO_PWMS 3
-#define MICROBIT_DISPLAY_PWM_PERIOD 1000
 
 enum PwmPersistence
 {
@@ -31,9 +30,8 @@ class DynamicPwm : public PwmOut
       * @param pin the name of the pin for the pwm to target
       * @param persistance the level of persistence for this pin PWM_PERSISTENCE_PERSISTENT (can not be replaced until freed, should only be used for system services really.) 
       * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.)
-      * @param period the frequency of the pwm channel in us.
       */
-    DynamicPwm(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT, int period = MICROBIT_DISPLAY_PWM_PERIOD);
+    DynamicPwm(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT);
     
     public: 
     
@@ -62,7 +60,7 @@ class DynamicPwm : public PwmOut
       * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
       * @endcode
       */
-    static DynamicPwm* allocate(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT, int period = MICROBIT_DISPLAY_PWM_PERIOD);
+    static DynamicPwm* allocate(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT);
     
     /**
       * Frees this DynamicPwm instance if the pointer is valid.
diff --git a/source/DynamicPwm.cpp b/source/DynamicPwm.cpp
index 8f82258..d61c6f4 100644
--- a/source/DynamicPwm.cpp
+++ b/source/DynamicPwm.cpp
@@ -48,10 +48,9 @@ void gpiote_reinit(PinName pin, PinName oldPin, uint8_t channel_number)
   * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.)
   * @param period the frequency of the pwm channel in us.
   */
-DynamicPwm::DynamicPwm(PinName pin, PwmPersistence persistence, int period) : PwmOut(pin)
+DynamicPwm::DynamicPwm(PinName pin, PwmPersistence persistence) : PwmOut(pin)
 {
     this->flags = persistence;
-    this->setPeriodUs(period);
 }
 
 /**
@@ -75,14 +74,13 @@ void DynamicPwm::redirect(PinName pin)
   * @param pin the name of the pin for the pwm to target
   * @param persistance the level of persistence for this pin PWM_PERSISTENCE_PERSISTENT (can not be replaced until freed, should only be used for system services really.) 
   * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.)
-  * @param period the frequency of the pwm channel in us.
   *
   * Example:
   * @code
   * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
   * @endcode
   */
-DynamicPwm* DynamicPwm::allocate(PinName pin, PwmPersistence persistence, int period)
+DynamicPwm* DynamicPwm::allocate(PinName pin, PwmPersistence persistence)
 {
     //try to find a blank spot first
     for(int i = 0; i < NO_PWMS; i++)
@@ -90,7 +88,7 @@ DynamicPwm* DynamicPwm::allocate(PinName pin, PwmPersistence persistence, int pe
         if(pwms[i] == NULL)
         {
             lastUsed = i;
-            pwms[i] = new DynamicPwm(pin, persistence, period);
+            pwms[i] = new DynamicPwm(pin, persistence);
             return pwms[i];
         }   
     }