diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9e2407aca1..3935f51de9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -63,6 +63,24 @@ pages:
     - gem install git_stats
     - git_stats generate --silent --out-path=public
 
+check_git_repos:
+  image: debian:buster-slim
+  stage: test
+  only:
+    - schedules
+  artifacts:
+    when: on_failure
+    expire_in: 1 month
+    paths:
+      - public
+  script:
+    - apt-get update
+    - apt-get -qy install --no-install-recommends ca-certificates git python3-yaml
+    - tools/check-git-repo-availability.py || export EXITVALUE=1
+    - test -d public || mkdir public
+    - cp `git status | grep -Eo 'metadata/.*\.yml'` public/ || true
+    - exit $EXITVALUE
+
 fdroid-buildserver:
   tags:
     - fdroid
diff --git a/tools/check-git-repo-availability.py b/tools/check-git-repo-availability.py
new file mode 100755
index 0000000000..bdb8b67767
--- /dev/null
+++ b/tools/check-git-repo-availability.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+import glob
+import re
+import subprocess
+import sys
+import yaml
+
+if len(sys.argv) > 1:
+    files = sys.argv[1:]
+else:
+    files = sorted(glob.glob('metadata/*.yml'))
+
+errors = dict()
+for f in files:
+    if not f.endswith('.yml'):
+        print('\n' + f + ':\nThis only runs on YAML files (.yml), ignoring.')
+        continue
+    with open(f) as fp:
+        data = yaml.load(fp)
+
+    url = data.get('Repo')
+    if not url or 'NoSourceSince' in data.keys():
+        continue
+    if data['RepoType'] != 'git':
+        continue
+
+    # from class vcs_git() in fdroidserver/common.py
+    git_config = [
+        '-c', 'core.askpass=/bin/true',
+        '-c', 'core.sshCommand=/bin/false',
+        '-c', 'url.https://.insteadOf=ssh://',
+    ]
+    for domain in ('bitbucket.org', 'github.com', 'gitlab.com'):
+        git_config.append('-c')
+        git_config.append('url.https://u:p@' + domain + '/.insteadOf=git@' + domain + ':')
+        git_config.append('-c')
+        git_config.append('url.https://u:p@' + domain + '.insteadOf=git://' + domain)
+        git_config.append('-c')
+        git_config.append('url.https://u:p@' + domain + '.insteadOf=https://' + domain)
+    env = {
+        'GIT_TERMINAL_PROMPT': '0',
+        'GIT_ASKPASS': '/bin/true',
+        'SSH_ASKPASS': '/bin/true',
+        'GIT_SSH': '/bin/false',  # for git < 2.3
+    }
+
+    p = subprocess.run(['git', ] + git_config + ['ls-remote', '--exit-code', '-h', url],
+                       env=env,
+                       capture_output=True)
+    if p.returncode != 0:
+        with open(f) as fp:
+            raw = fp.read()
+        with open(f, 'w') as fp:
+            fp.write(re.sub(r'(Repo|RepoType):.*\n{1,2}', r'', raw))
+            builds = data.get('Builds')
+            if builds:
+                versionName = str(builds[-1]['versionName'])
+                # if YAML will think its a float, quote it
+                try:
+                    float(versionName)
+                    fp.write("\nNoSourceSince: '" + versionName + "'")
+                except ValueError:
+                    fp.write("\nNoSourceSince: " + versionName)
+                fp.write('\n')
+
+        print('\n' + f + ':')
+        print(p.stderr.decode())
+        errors[f] = p.stderr
+
+errorcount = len(errors)
+if errorcount > 0:
+    print('\nFound', errorcount, 'errors.')
+sys.exit(errorcount)