diff --git a/rootfs/etc/s6-overlay/scripts/readsb b/rootfs/etc/s6-overlay/scripts/readsb
index db55fb5..2d780df 100755
--- a/rootfs/etc/s6-overlay/scripts/readsb
+++ b/rootfs/etc/s6-overlay/scripts/readsb
@@ -251,7 +251,7 @@ if [[ -n "$READSB_GAIN" ]]; then
     if [[ "${READSB_GAIN,,}" == "autogain" ]] && [[ -f /var/globe_history/autogain/gain ]]; then
         read -r gain < /var/globe_history/autogain/gain
     else
-        [[ "${READSB_GAIN,,}" == "autogain" ]] && gain="49.6" || gain="${READSB_GAIN}"
+        [[ "${READSB_GAIN,,}" == "autogain" ]] && gain="${READSB_AUTOGAIN_INITIAL_GAIN:-49.6}" || gain="${READSB_GAIN}"
     fi
     READSB_CMD+=("--gain=$gain")
 fi