diff --git a/backend/hp5400_internal.c b/backend/hp5400_internal.c
index 0e94d9df8..1d81358c1 100644
--- a/backend/hp5400_internal.c
+++ b/backend/hp5400_internal.c
@@ -165,6 +165,7 @@ GetSensors(THWParams * pHWParams, uint16_t *sensorMap)
    * Max 10 iterations for safety.
    *
    */
+  *sensorMap = 0;
   uint16_t thisSensorMap = 0;
   size_t iterCount = 10;
   do