diff --git a/src/receive.py b/src/receive.py
index 1e0ac46..2179643 100644
--- a/src/receive.py
+++ b/src/receive.py
@@ -43,7 +43,7 @@ def get_rssi_from_pkt(packet: list[int]):
 def get_rssi_from_reg(spi: SpiDev):
     return read_register(spi, RSSI)
 
-def get_signal_strength_rssi_raw(rssi_raw):
+def get_signal_strength_rssi_raw(rssi_raw: int) -> float:
     if rssi_raw >= 128:
         rssi_dec = rssi_raw - 256
     else: