diff --git a/src/main.cpp b/src/main.cpp
index 8ab19e2..29f54eb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -22,6 +22,12 @@ void setup() {
 
     analogWriteResolution(PWM_RESOLUTION);
 
+#ifdef ARDUINO_ARCH_ESP8266
+    analogWriteFreq(PWM_FREQUENCY);
+#else
+    analogWriteFrequency(PWM_FREQUENCY);
+#endif
+
     ApplicationInstance.begin();
 }
 
diff --git a/src/sys_constants.h b/src/sys_constants.h
index b880a2b..fa1ff02 100644
--- a/src/sys_constants.h
+++ b/src/sys_constants.h
@@ -21,6 +21,7 @@
 #define PIN_ENABLED                             (HIGH)
 
 #define PWM_RESOLUTION                          (14u)
+#define PWM_FREQUENCY                           (22000u)
 #define PWM_MAX_VALUE                           ((uint16_t)((1u << PWM_RESOLUTION) - 1))
 
 #define NTP_UPDATE_INTERVAL                     (24ul * 3600 * 1000)