diff --git a/apps/downloads/tests/test_views.py b/apps/downloads/tests/test_views.py
index b5eb75246..c1bed04a1 100644
--- a/apps/downloads/tests/test_views.py
+++ b/apps/downloads/tests/test_views.py
@@ -737,6 +737,31 @@ def test_v1_release_file_delete_by_release_still_works(self):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(len(self.get_json(response)), 0)
 
+    def test_unsupported_request_content_type_returns_415(self):
+        url = self.create_url("os")
+        cases = [
+            ("application/yaml", "name: Unsupported OS\nslug: unsupported-os\n"),
+            ("application/x-www-form-urlencoded", "name=Unsupported+OS&slug=unsupported-os"),
+        ]
+
+        for content_type, body in cases:
+            with self.subTest(content_type=content_type):
+                response = self.client.post(
+                    url, body, content_type=content_type, headers={"authorization": self.Authorization}
+                )
+
+                self.assertEqual(response.status_code, 415)
+                self.assertIn(content_type, response.json()["error"])
+                self.assertFalse(OS.objects.filter(slug="unsupported-os").exists())
+
+    def test_non_integer_detail_lookup_returns_404(self):
+        url = self.create_url("release", "latest")
+
+        response = self.client.get(url)
+
+        self.assertEqual(response.status_code, 404)
+        self.assertEqual(response.json()["error"], "Invalid resource lookup data provided (mismatched type).")
+
 
 class DownloadApiV2ViewsTest(BaseDownloadApiViewsTest, BaseDownloadTests, APITestCase):
     api_version = "v2"
diff --git a/pydotorg/resources.py b/pydotorg/resources.py
index 6c8f013d5..ef67cf48e 100644
--- a/pydotorg/resources.py
+++ b/pydotorg/resources.py
@@ -4,9 +4,9 @@
 from django.contrib.auth.models import AnonymousUser
 from tastypie.authentication import ApiKeyAuthentication
 from tastypie.authorization import Authorization
-from tastypie.exceptions import Unauthorized
-from tastypie.http import HttpUnauthorized
-from tastypie.resources import ModelResource
+from tastypie.exceptions import ImmediateHttpResponse, NotFound, Unauthorized, UnsupportedDeserializationFormat
+from tastypie.http import HttpNotFound, HttpUnauthorized, HttpUnsupportedMediaType
+from tastypie.resources import ModelResource, sanitize
 from tastypie.throttle import CacheThrottle
 
 API_KEY_AUTHENTICATED_ATTR = "_pydotorg_api_key_authenticated"
@@ -184,3 +184,21 @@ class Meta:
         detail_allowed_methods = ["get", "delete"]
         throttle = CacheThrottle(throttle_at=600)  # default is 150 req/hr
         abstract = True
+
+    def deserialize(self, request, data, format="application/json"):  # noqa: A002 - tastypie hook signature
+        """Return a 415 for unsupported request content types without firing the 500 signal."""
+        try:
+            return super().deserialize(request, data, format=format)
+        except UnsupportedDeserializationFormat as exc:
+            response = self.error_response(
+                request, {"error": sanitize(str(exc))}, response_class=HttpUnsupportedMediaType
+            )
+            raise ImmediateHttpResponse(response=response) from exc
+
+    def get_detail(self, request, **kwargs):
+        """Return a 404 for malformed detail lookups without firing the 500 signal."""
+        try:
+            return super().get_detail(request, **kwargs)
+        except NotFound as exc:
+            response = self.error_response(request, {"error": sanitize(str(exc))}, response_class=HttpNotFound)
+            raise ImmediateHttpResponse(response=response) from exc