diff --git a/.gitea/workflows/build-release.yml b/.gitea/workflows/build-release.yml
index 768735f..2fb34df 100644
--- a/.gitea/workflows/build-release.yml
+++ b/.gitea/workflows/build-release.yml
@@ -196,13 +196,17 @@ jobs:
       - name: Set app version from tag
         run: ./scripts/ci-set-version.sh
 
+      # Before init, and before the build: this edits tauri.conf.json, which is
+      # the input both of them read. `gen/android/app/tauri.properties` is an
+      # output of `android build` — it does not exist yet, and anything written
+      # there would be overwritten by the build anyway.
+      - name: Pin a monotonic Android versionCode
+        run: ./scripts/ci-android-version-code.sh
+
       - name: Initialise the Android project
         working-directory: src-tauri
         run: cargo tauri android init
 
-      - name: Pin a monotonic Android versionCode
-        run: ./scripts/ci-android-version-code.sh
-
       # Manifest, MainActivity, gradle config, and btleplug's Java backend.
       # `tauri android init` above regenerated gen/android and knows about none
       # of it — without this step the APK builds and then finds no trainer.
diff --git a/scripts/ci-android-version-code.sh b/scripts/ci-android-version-code.sh
index c359e68..51b760a 100755
--- a/scripts/ci-android-version-code.sh
+++ b/scripts/ci-android-version-code.sh
@@ -1,10 +1,15 @@
 #!/usr/bin/env sh
 # Pin an explicit, monotonic Android versionCode.
 #
-# `tauri android init` derives one from the semver in a way that is not
-# monotonic across a version series: 0.1.0 and 0.0.10 can collide, and Android
-# refuses to install an APK whose versionCode is not greater than the installed
-# one. A rider who cannot update is a rider who stops updating.
+# Tauri derives one from the semver as
+#
+#   major * 1000000 + minor * 1000 + patch
+#
+# which is monotonic but leaves the pre-1.0 series crowded down at the bottom of
+# the range: 0.1.0 is versionCode 1000. Android refuses to install an APK whose
+# versionCode is not greater than the installed one, and a rider who cannot
+# update is a rider who stops updating, so this pins the number rather than
+# leaving it to a default that a Tauri upgrade could change under us:
 #
 #   code = 1000 + major * 10000 + minor * 100 + patch
 #
@@ -12,20 +17,23 @@
 # semver order for any minor/patch below 100, which is well past where this
 # project will ever get.
 #
-# The 1000 floor is not decoration: `tauri android init` writes versionCode=1000
-# for 0.1.0 today, so anyone carrying a locally-built APK already has that
+# The 1000 floor is not decoration: Tauri's default gives 0.1.0 versionCode
+# 1000, so anyone carrying an APK from before this script already has that
 # number installed. A bare major/minor/patch code would be 100 — a *downgrade*,
 # which Android refuses outright.
 #
+# This writes bundle.android.versionCode in tauri.conf.json, NOT
+# gen/android/app/tauri.properties. tauri.properties is generated by
+# `cargo tauri android build`, not by `android init` — it does not exist at init
+# time, and the build overwrites it from the config on every run, so an edit
+# there is either a crash or a no-op. The config is the only durable input.
+#
 # POSIX sh: the runner's /bin/sh is dash. No here-strings, no \s in sed.
 set -e
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
-PROPS="$ROOT/src-tauri/gen/android/app/tauri.properties"
 CONF="$ROOT/src-tauri/tauri.conf.json"
 
-[ -f "$PROPS" ] || { echo "❌ $PROPS not found — run 'cargo tauri android init' first" >&2; exit 1; }
-
 VERSION=$(grep '"version"' "$CONF" | head -1 | sed -E 's/.*"version"[[:space:]]*:[[:space:]]*"([^"]+)".*/\1/')
 MAJ=$(echo "$VERSION" | cut -d. -f1)
 MIN=$(echo "$VERSION" | cut -d. -f2)
@@ -36,9 +44,18 @@ PAT=$(echo "$VERSION" | cut -d. -f3)
 CODE=$(( 1000 + MAJ * 10000 + MIN * 100 + PAT ))
 
 echo "version=$VERSION -> versionCode=$CODE"
-if grep -q '^tauri.android.versionCode=' "$PROPS"; then
-  sed -i "s/^tauri.android.versionCode=.*/tauri.android.versionCode=$CODE/" "$PROPS"
-else
-  echo "tauri.android.versionCode=$CODE" >> "$PROPS"
-fi
-cat "$PROPS"
+
+# The key is committed to tauri.conf.json, so a missing one means the config was
+# restructured and this sed would otherwise silently do nothing — shipping an
+# APK with a stale versionCode that no device would accept as an update.
+grep -q '"versionCode"' "$CONF" || {
+  echo "❌ no \"versionCode\" key in $CONF — add bundle.android.versionCode back" >&2
+  exit 1
+}
+sed -i "s/\"versionCode\"[[:space:]]*:[[:space:]]*[0-9]*/\"versionCode\": $CODE/" "$CONF"
+
+grep -q "\"versionCode\": $CODE" "$CONF" || {
+  echo "❌ failed to set versionCode to $CODE in $CONF" >&2
+  exit 1
+}
+grep -A2 '"android"' "$CONF"
diff --git a/src-tauri/tauri.conf.json b/src-tauri/tauri.conf.json
index 123fcf0..e5a891a 100644
--- a/src-tauri/tauri.conf.json
+++ b/src-tauri/tauri.conf.json
@@ -42,6 +42,9 @@
       "icons/icon.png"
     ],
     "category": "Utility",
+    "android": {
+      "versionCode": 1100
+    },
     "shortDescription": "Indoor cycling trainer control",
     "longDescription": "Control a smart trainer over BLE, ride gradient profiles and synthetic waveforms, and record the result."
   }