diff --git a/sonde-api-to-iot-core/lambda_function.py b/sonde-api-to-iot-core/lambda_function.py
index f72b356..1b394de 100644
--- a/sonde-api-to-iot-core/lambda_function.py
+++ b/sonde-api-to-iot-core/lambda_function.py
@@ -201,7 +201,7 @@ def telemetry_filter(telemetry):
 
     # Check Meisei sonde callsigns for validity.
     # meisei_ims returns a callsign of IMS100-xxxxxx until it receives the serial number, so we filter based on the x's being present or not.
-    if "MEISEI" in telemetry["type"]:
+    if "IMS100" in telemetry["type"] or "RS11G" in telemetry["type"]:
         meisei_callsign_valid = "x" not in _serial
     else:
         meisei_callsign_valid = False