diff --git a/README.md b/README.md
index 7f0a5c6..7dba3ac 100644
--- a/README.md
+++ b/README.md
@@ -515,14 +515,14 @@ docker exec -it tar1090 /usr/local/bin/viewadsb --cpr-focus 3D3ED0
 | -------------------------------------------- | ------------------------------------------------------------------------------------------------------ | -------------- |
 | `GRAPHS1090_DARKMODE`                        | If set to any value, `graphs1090` will be rendered in "dark mode".                                     | Unset          |
 | `GRAPHS1090_RRD_STEP`                        | Interval in seconds to feed data into RRD files.                                                       | `60`           |
-| `GRAPHS1090_SIZE`                            | Set graph size, possible values: `small`, `default`, `large`, `huge`, `custom`.                        | `default`      |
+| `GRAPHS1090_SIZE`                            | Set graph size, possible values: `small`, `default`, `large`, `huge`, `custom`.                        | `custom`       |
 | `GRAPHS1090_ALL_LARGE`                       | Make the small graphs as large as the big ones by setting to `yes`.                                    | `no`           |
 | `GRAPHS1090_FONT_SIZE`                       | Font size (relative to graph size).                                                                    | `10.0`         |
 | `GRAPHS1090_MAX_MESSAGES_LINE`               | Set to any value to draw a reference line at the maximum message rate.                                 | Unset          |
-| `GRAPHS1090_LARGE_WIDTH`                     | Defines the width of the larger graphs.                                                                | `1096`         |
-| `GRAPHS1090_LARGE_HEIGHT`                    | Defines the height of the larger graphs.                                                               | `235`          |
-| `GRAPHS1090_SMALL_WIDTH`                     | Defines the width of the smaller graphs.                                                               | `619`          |
-| `GRAPHS1090_SMALL_HEIGHT`                    | Defines the height of the smaller graphs.                                                              | `324`          |
+| `GRAPHS1090_LARGE_WIDTH`                     | Defines the width of the larger graphs. (if size is set to custom)                                     | `1096`         |
+| `GRAPHS1090_LARGE_HEIGHT`                    | Defines the height of the larger graphs. (if size is set to custom)                                    | `235`          |
+| `GRAPHS1090_SMALL_WIDTH`                     | Defines the width of the smaller graphs. (if size is set to custom)                                    | `619`          |
+| `GRAPHS1090_SMALL_HEIGHT`                    | Defines the height of the smaller graphs. (if size is set to custom)                                   | `324`          |
 | `GRAPHS1090_DISK_DEVICE`                     | Defines which disk device (`mmc0`, `sda`, `sdc`, etc) is shown. Leave empty for default device         | Unset          |
 | `GRAPHS1090_ETHERNET_DEVICE`                 | Defines which (wired) ethernet device (`eth0`, `enp0s`, etc) is shown. Leave empty for default device  | Unset          |
 | `GRAPHS1090_WIFI_DEVICE`                     | Defines which (wireless) WiFi device (`wlan0`, `wlp3s0`, etc) is shown. Leave empty for default device | Unset          |
diff --git a/rootfs/etc/s6-overlay/startup.d/08-graphs1090-init b/rootfs/etc/s6-overlay/startup.d/08-graphs1090-init
index e0fff06..270f00f 100755
--- a/rootfs/etc/s6-overlay/startup.d/08-graphs1090-init
+++ b/rootfs/etc/s6-overlay/startup.d/08-graphs1090-init
@@ -109,7 +109,7 @@ if [[ -n "${GRAPHS1090_SIZE}" ]] && [[ " small default large huge custom " =~ "
 elif [[ -n "${GRAPHS1090_SIZE}" ]] && [[ ! " small default large huge custom " =~ " ${GRAPHS1090_SIZE} " ]]; then
     echo "[$(date)][08-graphs1090] WARNING: GRAPHS1090_SIZE set to \"${GRAPHS1090_SIZE}\", which an invalid value!"
 else
-    sed -i "s|graph_size=.*|graph_size=default|g" /etc/default/graphs1090
+    sed -i "s|graph_size=.*|graph_size=custom|g" /etc/default/graphs1090
 fi
 
 # Make the small graphs as large as the big ones by setting to `yes`