diff --git a/README.md b/README.md
index b5c0c1c..2c80500 100644
--- a/README.md
+++ b/README.md
@@ -48,28 +48,22 @@ The timer runs 5 minutes after boot, then every 6 hours.
 update-notify [threshold]
 ```
 
-`threshold` is the minimum number of updates (repo + AUR) before update counts are shown. The default is 30.
-
-To change the threshold used by the timer, override the service:
-
-```
-systemctl --user edit update-notify.service
-```
-
-```ini
-[Service]
-ExecStart=
-ExecStart=/usr/bin/update-notify 50
-```
+`threshold` is the minimum number of updates (repo + AUR) before update counts are shown. It overrides the `THRESHOLD` setting below.
 
 ## Configuration
 
-These settings are at the top of the script:
+Settings are read from `$XDG_CONFIG_HOME/update-notify/config` (default `~/.config/update-notify/config`), a bash file that is sourced by the script. All settings are optional:
 
+- `THRESHOLD`: minimum number of updates before update counts are shown (default 30).
 - `AUR_REPO`: name of the local aurutils repository (default `aur-local`).
-- `KERNELS`: maps each stock kernel package to its custom build. Kernels where either package isn't installed are skipped.
+- `KERNELS`: maps each stock kernel package to its custom build (default: `linux`, `linux-lts` and `linux-zen` to `<name>-custom`). Kernels where either package isn't installed are skipped. Set `KERNELS=()` to disable the kernel check.
 
-Changes to the installed script are overwritten on upgrade, so change them in the source and rebuild the package.
+A commented sample config is installed with the package. To start from it:
+
+```
+mkdir -p ~/.config/update-notify
+cp /usr/share/doc/update-notify/config.example ~/.config/update-notify/config
+```
 
 Kernel versions are compared without `pkgrel`, so a stock packaging-only update doesn't trigger a rebuild reminder. A custom build already in the local repository but not installed yet counts as up to date.
 
diff --git a/config.example b/config.example
new file mode 100644
index 0000000..0558b4e
--- /dev/null
+++ b/config.example
@@ -0,0 +1,19 @@
+# update-notify configuration, sourced as bash.
+# Copy to ~/.config/update-notify/config and uncomment what you want to change.
+# The values shown are the defaults.
+
+# Minimum number of updates (repo + AUR) before update counts are shown.
+# The command-line argument takes precedence.
+#THRESHOLD=30
+
+# Name of the local aurutils repository.
+#AUR_REPO="aur-local"
+
+# Stock kernel package -> your custom build of it. Replaces the whole list;
+# kernels where either package isn't installed are skipped.
+# Set KERNELS=() to disable the kernel check.
+#KERNELS=(
+#    [linux]="linux-custom"
+#    [linux-lts]="linux-lts-custom"
+#    [linux-zen]="linux-zen-custom"
+#)
diff --git a/update-notify b/update-notify
index e60803a..385811c 100755
--- a/update-notify
+++ b/update-notify
@@ -2,20 +2,27 @@
 set -u
 
 # ---------------------------------------------------------------------------
-# Config
+# Config: defaults, overridden by the config file, then by the argument
 # ---------------------------------------------------------------------------
-threshold=${1:-30}
+THRESHOLD=30
 AUR_REPO="aur-local"
-# stock kernel package -> your custom build of it. Add or remove entries freely.
+# stock kernel package -> your custom build of it
 declare -A KERNELS=(
     [linux]="linux-custom"
     [linux-lts]="linux-lts-custom"
     [linux-zen]="linux-zen-custom"
 )
+config_file="${XDG_CONFIG_HOME:-$HOME/.config}/update-notify/config"
 state_dir="${XDG_STATE_HOME:-$HOME/.local/state}/update-notify"
 
-[[ $threshold =~ ^[0-9]+$ ]] || { echo "Threshold must be a number" >&2; exit 1; }
-threshold=$((10#$threshold))  # force base 10, so e.g. "08" isn't read as octal
+if [[ -r $config_file ]]; then
+    # shellcheck source=/dev/null
+    source "$config_file"
+fi
+THRESHOLD=${1:-$THRESHOLD}
+
+[[ $THRESHOLD =~ ^[0-9]+$ ]] || { echo "Threshold must be a number" >&2; exit 1; }
+THRESHOLD=$((10#$THRESHOLD))  # force base 10, so e.g. "08" isn't read as octal
 mkdir -p "$state_dir"
 
 # notify-send from cron/systemd needs the session bus address
@@ -122,7 +129,7 @@ done
 #   - update counts and reminders only when the threshold is reached
 # ---------------------------------------------------------------------------
 over_threshold=0
-(( updates >= threshold )) && over_threshold=1
+(( updates >= THRESHOLD )) && over_threshold=1
 
 parts=()
 if (( over_threshold )); then
diff --git a/update-notify.service b/update-notify.service
index dfa0bca..9fce723 100644
--- a/update-notify.service
+++ b/update-notify.service
@@ -2,5 +2,5 @@
 Description=Notify if updates are available
 
 [Service]
-ExecStart=/usr/bin/update-notify 30
+ExecStart=/usr/bin/update-notify
 Type=oneshot