diff --git a/kirovy/settings/testing.py b/kirovy/settings/testing.py
index 9f6582b..6099acd 100644
--- a/kirovy/settings/testing.py
+++ b/kirovy/settings/testing.py
@@ -15,4 +15,31 @@
     }
 }
 
+LOGGING = {
+    "version": 1,
+    "disable_existing_loggers": False,
+    "formatters": {
+        "tests_logging": {
+            "()": structlog.stdlib.ProcessorFormatter,
+            "processor": structlog.dev.ConsoleRenderer(),
+        },
+    },
+    "handlers": {
+        "pytest_console": {
+            "class": "logging.StreamHandler",
+            "formatter": "tests_logging",
+        },
+    },
+    "loggers": {
+        "kirovy": {
+            "handlers": ["pytest_console"],
+            "level": "DEBUG",
+        },
+        "django_structlog": {
+            "handlers": ["pytest_console"],
+            "level": "DEBUG",
+        },
+    },
+}
+
 # MEDIA_ROOT gets modified in common_fixtures.py in the tmp_media_root fixture.
diff --git a/kirovy/views/map_upload_views.py b/kirovy/views/map_upload_views.py
index af13f30..e7cdc0a 100644
--- a/kirovy/views/map_upload_views.py
+++ b/kirovy/views/map_upload_views.py
@@ -390,7 +390,31 @@ def post(self, request: KirovyRequest, format=None) -> KirovyResponse:
         legacy_map_service = legacy_upload.get_legacy_service_for_slug(game.slug.lower())(uploaded_file)
 
         map_hashes = self._get_file_hashes(ContentFile(legacy_map_service.file_contents_merged.read()))
-        self.verify_file_does_not_exist(map_hashes)
+        try:
+            self.verify_file_does_not_exist(map_hashes)
+        except KirovyValidationError:
+            # The old database just accepts duplicate uploads as if the map didn't exist.
+            # The client expects a successful upload in this scenario, so we need to mirror that.
+            _LOGGER.debug(
+                "Map already exists. Backwards compatible endpoint, returning success",
+                map_hash=map_hashes.sha1,
+                client_info=self.user_log_attrs,
+            )
+            existing_file = cnc_map.CncMapFile.objects.prefetch_related("cnc_map").get(hash_sha1=map_hashes.sha1)
+
+            return KirovyResponse(
+                ResultResponseData(
+                    message="Upload succeeded!",
+                    result={
+                        "cnc_map": existing_file.cnc_map.map_name,
+                        "cnc_map_file": existing_file.file.url,
+                        "cnc_map_id": existing_file.cnc_map_id,
+                        "extracted_preview_file": None,
+                        "download_url": f"/{game.slug}/{existing_file.hash_sha1}.zip",
+                    },
+                ),
+                status=status.HTTP_200_OK,
+            )
 
         # Make the map that we will attach the map file to.
         new_map = cnc_map.CncMap(
diff --git a/tests/test_views/test_backwards_compatibility.py b/tests/test_views/test_backwards_compatibility.py
index aea191d..2e19662 100644
--- a/tests/test_views/test_backwards_compatibility.py
+++ b/tests/test_views/test_backwards_compatibility.py
@@ -9,6 +9,7 @@
 
 from kirovy import typing as t
 from kirovy.models import CncGame, CncMapFile, CncMap
+from kirovy.objects.ui_objects import ResultResponseData
 from kirovy.response import KirovyResponse
 
 if t.TYPE_CHECKING:
@@ -128,3 +129,38 @@ def _download_and_check_hash(
     assert cnc_map_file.cnc_map.map_name == expected_map_name
     if ip_address:
         assert cnc_map_file.ip_address == ip_address
+
+
+def test_map_upload_duplicate_file_backwards_compatible(
+    client_anonymous,
+    zip_map_for_legacy_upload,
+    file_map_desert,
+    game_yuri,
+):
+    """
+    Test duplicate uploads for backwards compatible uploads.
+    Duplicates should just return successful like the old database.
+    """
+    url = "/upload"
+    original_extension = pathlib.Path(file_map_desert.name).suffix
+    upload_file, file_sha1 = zip_map_for_legacy_upload(file_map_desert)
+    upload_response: KirovyResponse[ResultResponseData] = client_anonymous.post(
+        url, {"file": upload_file, "game": game_yuri.slug}, format="multipart", content_type=None, REMOTE_ADDR="2.2.2.2"
+    )
+
+    assert upload_response.status_code == status.HTTP_200_OK
+    assert upload_response.data["result"]["download_url"] == f"/{game_yuri.slug}/{file_sha1}.zip"
+    original_map_id = upload_response.data["result"]["cnc_map_id"]
+
+    _download_and_check_hash(
+        client_anonymous, file_sha1, game_yuri, "desert", [original_extension], ip_address="2.2.2.2"
+    )
+
+    upload_file.seek(0)
+    duplicate_upload_response: KirovyResponse[ResultResponseData] = client_anonymous.post(
+        url, {"file": upload_file, "game": game_yuri.slug}, format="multipart", content_type=None, REMOTE_ADDR="1.2.2.2"
+    )
+
+    assert duplicate_upload_response.status_code == status.HTTP_200_OK
+    assert duplicate_upload_response.data["message"] == "Upload succeeded!"
+    assert duplicate_upload_response.data["result"]["cnc_map_id"] == original_map_id