diff --git a/gateway/actions.py b/gateway/actions.py
index aa3bca5..d66c8da 100644
--- a/gateway/actions.py
+++ b/gateway/actions.py
@@ -1,14 +1,27 @@
 import base64
+import logging
 import secrets
 
 from django.conf import settings
+from django.core.exceptions import ValidationError
+from django.core.validators import validate_slug
 
 from . import github, rap_api
 from .models import Job, Project, Run, User
 
 
+logger = logging.getLogger(__name__)
+
+
 def create_or_update_projects():
     for record in github.get_repo_metadata(settings.GITHUB_ORG):
+        try:
+            validate_slug(record["name"])
+        except ValidationError:
+            logger.warning(
+                "Ignoring GitHub repo with invalid slug name: %s", record["name"]
+            )
+            continue
         Project.objects.update_or_create(
             id=record["id"],
             defaults={
diff --git a/tests/test_actions.py b/tests/test_actions.py
index 1129624..f87482c 100644
--- a/tests/test_actions.py
+++ b/tests/test_actions.py
@@ -59,6 +59,27 @@ def test_create_or_update_projects():
     assert p3.description == "Description"
 
 
+def test_create_or_update_projects_ignores_invalid_slug_repos(caplog):
+    github_data = [
+        {"id": 123, "name": ".github", "description": "Ignored"},
+        {"id": 124, "name": "my.repo", "description": "Ignored"},
+        {"id": 456, "name": "test-2", "description": "Description"},
+    ]
+
+    with mocked_responses(get_data=github_data):
+        create_or_update_projects()
+
+    assert Project.objects.count() == 1
+    assert not Project.objects.filter(name=".github").exists()
+    assert not Project.objects.filter(name="my.repo").exists()
+    assert "Ignoring GitHub repo with invalid slug name: .github" in caplog.text
+    assert "Ignoring GitHub repo with invalid slug name: my.repo" in caplog.text
+
+    project = Project.objects.get(pk=456)
+    assert project.name == "test-2"
+    assert project.description == "Description"
+
+
 def test_create_or_update_users():
     User = get_user_model()
     github_data_1 = [