diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 761b7303..c0dba2a7 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -782,6 +782,24 @@ int16_t SX127x::setPreambleLength(size_t preambleLength) {
   return(RADIOLIB_ERR_UNKNOWN);
 }
 
+int16_t SX127x::setPreamblePolarity(int polarity) {
+  // set mode to standby
+  int16_t state = setMode(RADIOLIB_SX127X_STANDBY);
+  RADIOLIB_ASSERT(state);
+
+  // check active modem
+  uint8_t modem = getActiveModem();
+  if(modem == RADIOLIB_SX127X_LORA) {
+      return(RADIOLIB_ERR_WRONG_MODEM);
+  } else if(modem == RADIOLIB_SX127X_FSK_OOK) {
+    // set preamble polarity
+    state =this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_SYNC_CONFIG, polarity, 5, 5);
+    return(state);
+  }
+
+  return(RADIOLIB_ERR_UNKNOWN);
+}
+
 float SX127x::getFrequencyError(bool autoCorrect) {
   int16_t modem = getActiveModem();
   if(modem == RADIOLIB_SX127X_LORA) {
diff --git a/src/modules/SX127x/SX127x.h b/src/modules/SX127x/SX127x.h
index 9ef2890f..2abe7fe4 100644
--- a/src/modules/SX127x/SX127x.h
+++ b/src/modules/SX127x/SX127x.h
@@ -876,6 +876,13 @@ class SX127x: public PhysicalLayer {
     */
     int16_t setPreambleLength(size_t preambleLength) override;
 
+    /*!
+      \brief Sets FSK preamble polarity. Allowed values are RADIOLIB_SX127X_PREAMBLE_POLARITY_55 or RADIOLIB_SX127X_PREAMBLE_POLARITY_AA. Not allowed in LoRa mode.
+      \param polarity Preamble polarity bit in FSK mode).
+      \returns \ref status_codes
+    */
+    int16_t setPreamblePolarity(int polarity);
+
     /*!
       \brief Gets frequency error of the latest received packet.
       \param autoCorrect When set to true, frequency will be automatically corrected.