diff --git a/desktop/packaging/install.sh b/desktop/packaging/install.sh
index be5247e..a6e06b3 100755
--- a/desktop/packaging/install.sh
+++ b/desktop/packaging/install.sh
@@ -128,6 +128,25 @@ say "Installing ${version:-unknown} from the $channel channel"
 tmp="$(mktemp -d)"
 trap 'rm -rf "$tmp"' EXIT INT TERM
 
+# Tell the app which channel it was installed from. The installer is the only thing
+# that knows, and without this the app kept its own `stable` default and a dev install
+# checked the stable feed — which advertises an OLDER version — reporting "up to date"
+# forever (issue 2183).
+#
+# A plain file rather than a write into the app's SQLite store: shell has no business
+# knowing that schema, and a file it can't misread is the narrowest possible contract.
+# The app reads it at startup (src-tauri/src/update.rs, INSTALL_MARKER) and only acts
+# when the value CHANGED, so switching channel in the app isn't undone on next launch.
+#
+# The directory is Tauri's app-data dir for identifier com.fabledsword.thoughtsync;
+# both sides hardcode it, so a change to the identifier has to change both.
+record_channel() {
+  marker_dir="${XDG_DATA_HOME:-$HOME/.local/share}/com.fabledsword.thoughtsync"
+  # Best-effort: a failure here costs the channel setting, not the install, and a
+  # native install run as root would only be writing into root's home anyway.
+  mkdir -p "$marker_dir" 2>/dev/null && printf '%s\n' "$channel" > "$marker_dir/install-channel" 2>/dev/null || true
+}
+
 # Both native paths install system-wide, so they need root. Resolved once here
 # rather than duplicated per branch; the AppImage path below never calls this.
 need_root() {
@@ -163,6 +182,7 @@ if have pacman && [ -n "$pkg_url" ]; then
   curl -fSL -o "$pkg_file" "$pkg_url"
   need_root
   $sudo pacman -U --noconfirm "$pkg_file"
+  record_channel
   say "Done. Launch ThoughtSync from your application menu, or run thoughtsync."
   native_update_note
   exit 0
@@ -178,6 +198,7 @@ if have dpkg && have apt-get && [ -n "$deb_url" ]; then
   # unconfigured, so `apt-get -f install` is what actually completes that path.
   $sudo apt-get install -y "$tmp/thoughtsync.deb" ||
     { $sudo dpkg -i "$tmp/thoughtsync.deb" || true; $sudo apt-get -f install -y; }
+  record_channel
   say "Done. Launch ThoughtSync from your application menu."
   native_update_note
   exit 0
@@ -233,12 +254,13 @@ have update-desktop-database && update-desktop-database "$apps_menu" >/dev/null
 mkdir -p "$HOME/.local/bin"
 ln -sf "$dest" "$HOME/.local/bin/thoughtsync"
 
+record_channel
+
 say "Installed to $dest"
 printf '    Launch it from your application menu, or run \033[1mthoughtsync\033[0m'
 printf ' (if ~/.local/bin is on your PATH).\n'
-# The AppImage CAN update itself, but the app's own channel is a separate,
-# stable-by-default setting — installing from dev here does not move it.
+# This is the one path where the app can update itself, so say what it will follow.
 if [ "$channel" = "dev" ]; then
-  printf '    You installed from the \033[1mdev\033[0m channel — set the app to match in\n'
-  printf '    Sync → App updates → Development, or in-app updates will follow stable.\n'
+  printf '    In-app updates will follow the \033[1mdev\033[0m channel.'
+  printf ' Change it in Sync → App updates.\n'
 fi
diff --git a/desktop/src-tauri/src/lib.rs b/desktop/src-tauri/src/lib.rs
index 02de8c5..1ac2b29 100644
--- a/desktop/src-tauri/src/lib.rs
+++ b/desktop/src-tauri/src/lib.rs
@@ -72,6 +72,9 @@ pub fn run() {
             log::info!("opening local store: {}", db_path.display());
             let db = local::open(&db_path)?;
             log::info!("local store ready — {}", local::summary(&db));
+            // Before anything can ask what channel we're on: the installer left a note
+            // in this directory saying which one the user picked (issue 2183).
+            update::adopt_installer_channel(&db, &dir);
             sweep_local_trash(&db);
             app.manage(db);
             // Attachment bytes live beside the database, filed by content hash, so a
diff --git a/desktop/src-tauri/src/update.rs b/desktop/src-tauri/src/update.rs
index ecfc7e0..1537863 100644
--- a/desktop/src-tauri/src/update.rs
+++ b/desktop/src-tauri/src/update.rs
@@ -15,6 +15,8 @@
 //! half exists only as a CI secret, and is generated by the operator — a release
 //! signing key that has passed through anyone else's hands is not a signing key.
 
+use std::path::Path;
+
 use serde::{Deserialize, Serialize};
 use tauri::State;
 use tauri_plugin_updater::UpdaterExt;
@@ -26,6 +28,16 @@ const FEED_BASE: &str = "https://git.fabledsword.com/bvandeusen/thoughtsync/rele
 
 const CHANNEL_PREF: &str = "update_channel";
 
+/// The channel the app follows, as recorded by whatever installed it. Written into
+/// the app-data directory by `desktop/packaging/install.sh`; both sides must agree on
+/// this name.
+const INSTALL_MARKER: &str = "install-channel";
+
+/// The marker value we last acted on. Deliberately separate from `CHANNEL_PREF`: it
+/// records what the INSTALLER said, so the two can be compared and a change told apart
+/// from a repeat. See `adopt_installer_channel`.
+const CHANNEL_SEED_PREF: &str = "update_channel_seed";
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub enum Channel {
@@ -50,6 +62,22 @@ impl Channel {
         }
     }
 
+    /// Strict parse, for the installer's marker file only.
+    ///
+    /// Unrecognized reads as "no opinion" here rather than as `stable` (which is what
+    /// `parse` does), because the two are asked different questions. `parse` reads a
+    /// pref that is definitely *this app's* setting, so it has to answer with a
+    /// channel. The marker is a file written by something else, and a truncated or
+    /// hand-edited one must not silently move someone OFF the channel they chose.
+    /// Ignoring it is the only reading that can't do harm in either direction.
+    fn from_marker(raw: &str) -> Option<Self> {
+        match raw.trim() {
+            "stable" => Some(Channel::Stable),
+            "dev" => Some(Channel::Dev),
+            _ => None,
+        }
+    }
+
     fn feed_url(self) -> String {
         format!("{FEED_BASE}/{}/latest.json", self.as_str())
     }
@@ -89,6 +117,62 @@ fn self_update_blocker() -> Option<String> {
     None
 }
 
+/// Adopt the channel the installer recorded, when it differs from the one we last
+/// adopted. Called once at startup, before the frontend can ask what the channel is.
+///
+/// The installer knows which channel the user asked for; the app is what acts on it.
+/// Until this existed, `install.sh --channel dev` left the pref at its `stable`
+/// default, so a dev build checked the stable feed — which advertises an OLDER
+/// version — and reported "up to date" forever (issue 2183). Two places held the same
+/// decision and only one of them was set.
+///
+/// Comparing against the last-adopted value, rather than only seeding when the pref is
+/// unset, is what makes both directions work: choosing a channel in the app sticks
+/// across launches (the marker hasn't changed since we adopted it), while re-running
+/// the installer on a DIFFERENT channel is honoured (it has). Seeding-when-unset would
+/// have fixed only the very first install and left the second one silently wrong.
+///
+/// Every failure is logged and stepped over. No marker at all is the ordinary state of
+/// a build installed some other way — from source, from a downloaded AppImage, or by a
+/// Windows installer that has no channel concept — and none of that should keep the
+/// app from opening.
+pub fn adopt_installer_channel(db: &Db, data_dir: &Path) {
+    let path = data_dir.join(INSTALL_MARKER);
+    let Ok(raw) = std::fs::read_to_string(&path) else {
+        return;
+    };
+    let Some(channel) = Channel::from_marker(&raw) else {
+        log::warn!(
+            "ignoring an unreadable install channel marker at {}",
+            path.display()
+        );
+        return;
+    };
+    match adopt(db, channel) {
+        Ok(true) => log::info!(
+            "following the {} update channel, as recorded by the installer",
+            channel.as_str()
+        ),
+        Ok(false) => {}
+        Err(e) => log::warn!("could not apply the installer's update channel: {e}"),
+    }
+}
+
+/// Apply `channel` unless we already applied this same marker value. Returns whether
+/// anything changed.
+fn adopt(db: &Db, channel: Channel) -> Result<bool, String> {
+    let conn = db.0.lock().map_err(|e| e.to_string())?;
+    let adopted = store::pref(&conn, CHANNEL_SEED_PREF).map_err(|e| e.to_string())?;
+    // Already acted on this marker — whatever the pref says now is the user's own
+    // choice, and re-applying would quietly undo it.
+    if adopted.as_deref() == Some(channel.as_str()) {
+        return Ok(false);
+    }
+    store::set_pref(&conn, CHANNEL_PREF, channel.as_str()).map_err(|e| e.to_string())?;
+    store::set_pref(&conn, CHANNEL_SEED_PREF, channel.as_str()).map_err(|e| e.to_string())?;
+    Ok(true)
+}
+
 fn read_channel(db: &State<'_, Db>) -> Result<Channel, String> {
     let conn = db.0.lock().map_err(|e| e.to_string())?;
     let raw = store::pref(&conn, CHANNEL_PREF).map_err(|e| e.to_string())?;
@@ -224,6 +308,100 @@ fn describe_check_error(detail: &str) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::local::schema;
+    use rusqlite::Connection;
+    use std::sync::Mutex;
+
+    fn db() -> Db {
+        let conn = Connection::open_in_memory().expect("in-memory db");
+        schema::migrate(&conn).expect("migrate");
+        Db(Mutex::new(conn))
+    }
+
+    /// The channel `update_check` would actually use.
+    fn effective(db: &Db) -> Channel {
+        let conn = db.0.lock().expect("lock");
+        store::pref(&conn, CHANNEL_PREF)
+            .expect("read pref")
+            .as_deref()
+            .map(Channel::parse)
+            .unwrap_or(Channel::Stable)
+    }
+
+    fn set_channel(db: &Db, channel: Channel) {
+        let conn = db.0.lock().expect("lock");
+        store::set_pref(&conn, CHANNEL_PREF, channel.as_str()).expect("set pref");
+    }
+
+    /// A scratch directory holding a marker file, named uniquely so tests can run in
+    /// parallel. Dropped by the OS' temp cleanup; nothing here is worth a new dependency.
+    fn data_dir_with_marker(contents: &str) -> std::path::PathBuf {
+        let dir = std::env::temp_dir().join(format!("ts-marker-{}", uuid::Uuid::new_v4()));
+        std::fs::create_dir_all(&dir).expect("scratch dir");
+        std::fs::write(dir.join(INSTALL_MARKER), contents).expect("write marker");
+        dir
+    }
+
+    #[test]
+    fn a_dev_install_follows_the_dev_channel() {
+        // The bug this whole mechanism exists for (2183): the installer knew, the app
+        // didn't, and a dev install checked the stable feed forever.
+        let db = db();
+        assert_eq!(
+            effective(&db),
+            Channel::Stable,
+            "default before any install"
+        );
+        adopt_installer_channel(&db, &data_dir_with_marker("dev\n"));
+        assert_eq!(effective(&db), Channel::Dev);
+    }
+
+    #[test]
+    fn choosing_a_channel_in_the_app_survives_the_next_launch() {
+        // Adoption runs on EVERY startup, so the marker must not keep re-asserting
+        // itself over a choice the user made afterwards.
+        let db = db();
+        let dir = data_dir_with_marker("dev");
+        adopt_installer_channel(&db, &dir);
+        set_channel(&db, Channel::Stable);
+        adopt_installer_channel(&db, &dir);
+        assert_eq!(effective(&db), Channel::Stable);
+    }
+
+    #[test]
+    fn reinstalling_on_a_different_channel_moves_the_app() {
+        // The half a seed-only-when-unset fix would have missed: install stable, then
+        // install dev. The pref is already set, but the user just asked for dev.
+        let db = db();
+        adopt_installer_channel(&db, &data_dir_with_marker("stable"));
+        assert_eq!(effective(&db), Channel::Stable);
+        adopt_installer_channel(&db, &data_dir_with_marker("dev"));
+        assert_eq!(effective(&db), Channel::Dev);
+    }
+
+    #[test]
+    fn a_damaged_marker_changes_nothing() {
+        // Ignored, NOT read as stable — a corrupt file must not move someone off the
+        // channel they're on.
+        let db = db();
+        set_channel(&db, Channel::Dev);
+        adopt_installer_channel(&db, &data_dir_with_marker("de"));
+        assert_eq!(effective(&db), Channel::Dev);
+        assert_eq!(Channel::from_marker("nightly"), None);
+        assert_eq!(Channel::from_marker(""), None);
+        assert_eq!(Channel::from_marker(" dev\n"), Some(Channel::Dev));
+    }
+
+    #[test]
+    fn no_marker_at_all_is_not_an_error() {
+        // Built from source, or installed by anything that isn't install.sh.
+        let db = db();
+        set_channel(&db, Channel::Dev);
+        let empty = std::env::temp_dir().join(format!("ts-nomarker-{}", uuid::Uuid::new_v4()));
+        std::fs::create_dir_all(&empty).expect("scratch dir");
+        adopt_installer_channel(&db, &empty);
+        assert_eq!(effective(&db), Channel::Dev);
+    }
 
     #[test]
     fn each_channel_has_its_own_fixed_feed() {