diff --git a/.gitea/workflows/publish.yml b/.gitea/workflows/publish.yml
index 28efef1..3cf352e 100644
--- a/.gitea/workflows/publish.yml
+++ b/.gitea/workflows/publish.yml
@@ -24,23 +24,127 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install build twine
 
+      - name: Check publishing credentials
+        env:
+          TWINE_USERNAME: ${{ secrets.REGISTRY_USER }}
+          TWINE_PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}
+        run: |
+          test -n "$TWINE_USERNAME" || { echo "Missing REGISTRY_USER secret"; exit 1; }
+          test -n "$TWINE_PASSWORD" || { echo "Missing REGISTRY_PASSWORD secret"; exit 1; }
+
       - name: Set CI package version
+        env:
+          TWINE_USERNAME: ${{ secrets.REGISTRY_USER }}
+          TWINE_PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}
         run: |
           python - <<'PY'
           from pathlib import Path
+          from urllib.error import HTTPError
+          from urllib.parse import urlencode
+          from urllib.request import Request, urlopen
+          import base64
+          import json
           import os
           import re
+          import tomllib
 
-          path = Path('tryton.cfg')
-          text = path.read_text()
-          match = re.search(r'(?m)^version=(.+)$', text)
-          if not match:
+          OWNER = 'tryton-do'
+          PACKAGE_TYPE = 'pypi'
+          API_ROOT = 'https://gitea.joseagrc.com/api/v1'
+
+          def normalize(name):
+              return re.sub(r'[-_.]+', '-', name).lower()
+
+          cfg_path = Path('tryton.cfg')
+          cfg_text = cfg_path.read_text()
+          cfg_match = re.search(r'(?m)^version=(.+)$', cfg_text)
+          if not cfg_match:
               raise SystemExit('tryton.cfg has no version entry')
-          base_version = match.group(1).strip()
-          run_number = os.environ.get('GITHUB_RUN_NUMBER', '0')
-          ci_version = f'{base_version}.post{run_number}'
-          text = re.sub(r'(?m)^version=.+$', f'version={ci_version}', text)
-          path.write_text(text)
+          base_version = cfg_match.group(1).strip()
+          version_match = re.fullmatch(r'(\d+)\.(\d+)\.(\d+)', base_version)
+          if not version_match:
+              raise SystemExit(
+                  f'tryton.cfg version must be X.Y.Z, got {base_version!r}')
+          major, minor, patch = map(int, version_match.groups())
+
+          pyproject = tomllib.loads(Path('pyproject.toml').read_text())
+          package_name = pyproject['project']['name']
+          normalized_name = normalize(package_name)
+
+          username = os.environ['TWINE_USERNAME']
+          password = os.environ['TWINE_PASSWORD']
+          token = base64.b64encode(
+              f'{username}:{password}'.encode()).decode()
+
+          def request_json(path, params=None, missing_ok=False):
+              url = f'{API_ROOT}{path}'
+              if params:
+                  url = f'{url}?{urlencode(params)}'
+              request = Request(url, headers={
+                  'Accept': 'application/json',
+                  'Authorization': f'Basic {token}',
+                  })
+              try:
+                  with urlopen(request, timeout=30) as response:
+                      return json.load(response)
+              except HTTPError as error:
+                  if missing_ok and error.code == 404:
+                      return []
+                  raise
+
+          def collect_versions(payload, package_specific=False):
+              versions = []
+              if isinstance(payload, list):
+                  for item in payload:
+                      versions.extend(collect_versions(item, package_specific))
+              elif isinstance(payload, dict):
+                  item_name = payload.get('name') or payload.get('package_name')
+                  item_type = payload.get('type') or payload.get('package_type')
+                  item_version = payload.get('version')
+                  if item_version and (
+                          package_specific
+                          or (item_type == PACKAGE_TYPE
+                              and normalize(item_name or '') == normalized_name)):
+                      versions.append(str(item_version))
+                  for value in payload.values():
+                      if isinstance(value, (list, dict)):
+                          versions.extend(collect_versions(value, package_specific))
+              return versions
+
+          versions = []
+          for page in range(1, 11):
+              payload = request_json(
+                  f'/packages/{OWNER}/{PACKAGE_TYPE}/{package_name}',
+                  {'page': page, 'limit': 100},
+                  missing_ok=True)
+              page_versions = collect_versions(payload, package_specific=True)
+              versions.extend(page_versions)
+              if not page_versions:
+                  break
+
+          for page in range(1, 11):
+              payload = request_json(
+                  f'/packages/{OWNER}',
+                  {'page': page, 'limit': 100, 'type': PACKAGE_TYPE,
+                   'q': package_name})
+              page_versions = collect_versions(payload)
+              versions.extend(page_versions)
+              if not page_versions:
+                  break
+
+          patch_pattern = re.compile(rf'^{major}\.{minor}\.(\d+)$')
+          patches = [patch]
+          for version in set(versions):
+              match = patch_pattern.fullmatch(version)
+              if match:
+                  patches.append(int(match.group(1)))
+
+          ci_version = f'{major}.{minor}.{max(patches) + 1}'
+          cfg_text = re.sub(
+              r'(?m)^version=.+$', f'version={ci_version}', cfg_text)
+          cfg_path.write_text(cfg_text)
+          print(f'Package name: {package_name}')
+          print(f'Published versions found: {sorted(set(versions))}')
           print(f'Package version: {ci_version}')
           PY
 
@@ -52,14 +156,6 @@ jobs:
         run: |
           python -m twine check dist/*
 
-      - name: Check publishing credentials
-        env:
-          TWINE_USERNAME: ${{ secrets.REGISTRY_USER }}
-          TWINE_PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}
-        run: |
-          test -n "$TWINE_USERNAME" || { echo "Missing REGISTRY_USER secret"; exit 1; }
-          test -n "$TWINE_PASSWORD" || { echo "Missing REGISTRY_PASSWORD secret"; exit 1; }
-
       - name: Publish to Gitea PyPI registry
         env:
           TWINE_USERNAME: ${{ secrets.REGISTRY_USER }}