diff --git a/.github/workflows/native-platforms.yml b/.github/workflows/native-platforms.yml
index 8a8f0cfe..df4849b0 100644
--- a/.github/workflows/native-platforms.yml
+++ b/.github/workflows/native-platforms.yml
@@ -80,7 +80,7 @@ jobs:
       - name: Install preflight tools
         run: |
           sudo apt-get update
-          sudo apt-get install -y appstream desktop-file-utils dpkg-dev
+          sudo apt-get install -y appstream desktop-file-utils dpkg-dev gettext
       - name: Check release metadata and packaging
         id: version
         env:
@@ -91,6 +91,9 @@ jobs:
           else
             bash scripts/check-release.sh
           fi
+      - name: Require complete Spanish and Russian translations
+        if: github.event_name == 'push' && github.ref_type == 'tag'
+        run: bash scripts/check-translation-completeness.sh es ru
 
   linux:
     needs: metadata
diff --git a/.github/workflows/quality.yml b/.github/workflows/quality.yml
index 33b60b23..3753d80e 100644
--- a/.github/workflows/quality.yml
+++ b/.github/workflows/quality.yml
@@ -58,6 +58,25 @@ jobs:
           key: quality-default
       - name: Check formatting
         run: cargo fmt --all -- --check
+      - name: Leave translation catalogs to Weblate
+        # Weblate's msgmerge add-on owns lang/*/LC_MESSAGES; edits from other
+        # branches conflict with its pending commits and lock the component.
+        if: >-
+          github.event_name == 'pull_request' &&
+          !(github.head_ref == 'weblate-flectar-mail-mail' &&
+            github.event.pull_request.head.repo.full_name == github.repository)
+        shell: bash
+        run: |
+          set -euo pipefail
+          # The checkout is the pull request's merge commit; its first parent
+          # is the base branch.
+          git fetch --quiet --deepen=1 origin "$GITHUB_SHA"
+          changed=$(git diff --name-only HEAD^1 HEAD -- 'lang/*/LC_MESSAGES/*.po')
+          if [[ -n $changed ]]; then
+            printf '%s\n' "$changed"
+            echo "::error::Only Weblate edits lang/*/LC_MESSAGES. Commit lang/flectar-mail.pot alone (scripts/update-translation-template.sh) and translate on https://translate.flectar.com/."
+            exit 1
+          fi
       - name: Validate repository support files
         shell: bash
         run: |
@@ -123,14 +142,6 @@ jobs:
         run: |
           cargo install slint-tr-extractor --version 1.18.1 --locked
           bash scripts/check-translations.sh
-          for language in es ru; do
-            catalog="lang/$language/LC_MESSAGES/flectar-mail.po"
-            msgfmt --check --check-header --check-format \
-              -o "/tmp/flectar-mail-$language.mo" "$catalog"
-            test -z "$(msgattrib --untranslated --no-obsolete "$catalog")"
-            test -z "$(msgattrib --only-fuzzy --no-obsolete "$catalog")"
-            test -z "$(msgattrib --only-obsolete "$catalog")"
-          done
       - name: Run the default test suite
         run: cargo test --workspace --all-targets --locked
       - name: Test the vendored Blitz patches
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f6a7ef9b..cf1a8aa9 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -14,6 +14,15 @@ and safe for a mail client that handles private user data.
 ## Translations
 
 Translate the application through [Weblate](https://translate.flectar.com/).
+Weblate owns the catalogs in `lang/*/LC_MESSAGES/` and sends them back as pull
+requests, so other pull requests must not edit them. When a change adds, edits
+or moves translatable strings in `.slint` files, run
+`scripts/update-translation-template.sh` (it needs `slint-tr-extractor` 1.18.1)
+and commit only `lang/flectar-mail.pot`. Weblate merges the template into every
+language after the change reaches `main`. Releases require complete Spanish and
+Russian translations, which `scripts/check-translation-completeness.sh es ru`
+checks.
+
 README translations are maintained directly in this repository:
 
 - Use [README.md](README.md) as the source and add
diff --git a/scripts/check-translation-completeness.sh b/scripts/check-translation-completeness.sh
new file mode 100755
index 00000000..395653c1
--- /dev/null
+++ b/scripts/check-translation-completeness.sh
@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Fails unless each given language translates every string in the current
+# template, with no fuzzy entries. Releases require this for Spanish and
+# Russian; finish missing strings on Weblate, then merge its pull request.
+set -euo pipefail
+
+repo_root=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
+command -v msgmerge >/dev/null || {
+  echo "GNU gettext is required" >&2
+  exit 1
+}
+if [[ $# -eq 0 ]]; then
+  echo "usage: $0 LANGUAGE..." >&2
+  exit 2
+fi
+
+work_dir=$(mktemp -d)
+trap 'rm -rf -- "$work_dir"' EXIT
+cd "$repo_root"
+
+status=0
+for language in "$@"; do
+  merged="$work_dir/$language.po"
+  msgmerge --quiet --no-fuzzy-matching --output-file "$merged" \
+    "lang/$language/LC_MESSAGES/flectar-mail.po" lang/flectar-mail.pot
+  untranslated=$(msgattrib --untranslated --no-obsolete "$merged")
+  fuzzy=$(msgattrib --only-fuzzy --no-obsolete "$merged")
+  if [[ -n $untranslated || -n $fuzzy ]]; then
+    printf '%s: ' "$language" >&2
+    LC_ALL=C msgfmt --statistics -o /dev/null "$merged"
+    status=1
+  fi
+done
+exit "$status"
diff --git a/scripts/check-translations.sh b/scripts/check-translations.sh
index 434adc5d..546019cd 100644
--- a/scripts/check-translations.sh
+++ b/scripts/check-translations.sh
@@ -2,11 +2,7 @@
 set -euo pipefail
 
 repo_root=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
-command -v slint-tr-extractor >/dev/null || {
-  echo "slint-tr-extractor 1.18.1 is required" >&2
-  exit 1
-}
-command -v msgmerge >/dev/null || {
+command -v msgfmt >/dev/null || {
   echo "GNU gettext is required" >&2
   exit 1
 }
@@ -15,26 +11,17 @@ work_dir=$(mktemp -d)
 trap 'rm -rf -- "$work_dir"' EXIT
 cd "$repo_root"
 
-# Preview and screenshot scripts use temporary hidden .slint files.
-find ui -type f -name '*.slint' ! -name '.*' -print0 \
-  | sort -z \
-  | xargs -0 slint-tr-extractor --no-default-translation-context \
-      --package-name flectar-mail --package-version 0.1.0 \
-      -o "$work_dir/flectar-mail.pot"
+bash scripts/update-translation-template.sh "$work_dir/flectar-mail.pot"
+if ! diff -u lang/flectar-mail.pot "$work_dir/flectar-mail.pot"; then
+  echo "lang/flectar-mail.pot is out of date; run scripts/update-translation-template.sh." >&2
+  exit 1
+fi
 
-# Extraction timestamps are intentionally volatile; compare every semantic
-# catalog line while ignoring only that generated header field.
-diff -u \
-  <(sed '/^"POT-Creation-Date:/d' lang/flectar-mail.pot) \
-  <(sed '/^"POT-Creation-Date:/d' "$work_dir/flectar-mail.pot")
-
-for language in da de es fr it ja nl ru tr zh_Hans; do
-  msgmerge --quiet --no-fuzzy-matching \
-    --output-file "$work_dir/flectar-mail-$language.po" \
-    "lang/$language/LC_MESSAGES/flectar-mail.po" "$work_dir/flectar-mail.pot"
-  diff -u \
-    <(sed '/^"POT-Creation-Date:/d' "lang/$language/LC_MESSAGES/flectar-mail.po") \
-    <(sed '/^"POT-Creation-Date:/d' "$work_dir/flectar-mail-$language.po")
+# Weblate writes the catalogs and merges new template strings into them, so
+# they may lag the template and keep Weblate's line wrapping. Check only that
+# each one compiles.
+for catalog in lang/*/LC_MESSAGES/flectar-mail.po; do
+  msgfmt --check --check-header --check-format -o /dev/null "$catalog"
 done
 
 bash scripts/check-ui-message-catalog.sh
diff --git a/scripts/update-translation-template.sh b/scripts/update-translation-template.sh
new file mode 100755
index 00000000..994c5100
--- /dev/null
+++ b/scripts/update-translation-template.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Regenerates the translation template from the .slint sources. Only the
+# template lives in this repository's pull requests; Weblate merges it into
+# lang/*/LC_MESSAGES/flectar-mail.po with its msgmerge add-on.
+set -euo pipefail
+
+repo_root=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
+template="$repo_root/lang/flectar-mail.pot"
+output=${1:-$template}
+command -v slint-tr-extractor >/dev/null || {
+  echo "slint-tr-extractor 1.18.1 is required" >&2
+  exit 1
+}
+
+work_dir=$(mktemp -d)
+trap 'rm -rf -- "$work_dir"' EXIT
+cd "$repo_root"
+
+# Preview and screenshot scripts use temporary hidden .slint files.
+find ui -type f -name '*.slint' ! -name '.*' -print0 \
+  | sort -z \
+  | xargs -0 slint-tr-extractor --no-default-translation-context \
+      --package-name flectar-mail --package-version 0.1.0 \
+      -o "$work_dir/flectar-mail.pot"
+
+# Keep the committed creation date so that unchanged strings give an
+# unchanged template; Weblate copies this header into every catalog.
+creation_date=$(grep -m1 '^"POT-Creation-Date:' "$template" || true)
+if [[ -n $creation_date ]]; then
+  CREATION_DATE=$creation_date awk '
+    !done && /^"POT-Creation-Date:/ { print ENVIRON["CREATION_DATE"]; done = 1; next }
+    { print }
+  ' "$work_dir/flectar-mail.pot" >"$work_dir/dated.pot"
+  mv "$work_dir/dated.pot" "$work_dir/flectar-mail.pot"
+fi
+mv "$work_dir/flectar-mail.pot" "$output"