diff --git a/radio/src/io/frsky_firmware_update.cpp b/radio/src/io/frsky_firmware_update.cpp
index b9a205638..cca50d521 100644
--- a/radio/src/io/frsky_firmware_update.cpp
+++ b/radio/src/io/frsky_firmware_update.cpp
@@ -512,7 +512,7 @@ const char * FrskyChipFirmwareUpdate::sendUpgradeCommand(char command, uint32_t
   return status == 0x00 ? nullptr : "Upgrade failed";
 }
 
-const char * FrskyChipFirmwareUpdate::sendUpgradeData(uint8_t index, uint8_t * data)
+const char * FrskyChipFirmwareUpdate::sendUpgradeData(uint32_t index, uint8_t * data)
 {
   telemetryPortSetDirectionOutput();
 
diff --git a/radio/src/io/frsky_firmware_update.h b/radio/src/io/frsky_firmware_update.h
index 768bd0e19..8ea504463 100644
--- a/radio/src/io/frsky_firmware_update.h
+++ b/radio/src/io/frsky_firmware_update.h
@@ -105,7 +105,7 @@ class FrskyChipFirmwareUpdate {
     const char * waitAnswer(uint8_t & status);
     const char * startBootloader();
     const char * sendUpgradeCommand(char command, uint32_t packetsCount);
-    const char * sendUpgradeData(uint8_t index, uint8_t * data);
+    const char * sendUpgradeData(uint32_t index, uint8_t * data);
 
     const char * doFlashFirmware(const char * filename);
 };