diff --git a/src/backend/app/config.py b/src/backend/app/config.py
index f4c895cb6c..ba4a709d47 100644
--- a/src/backend/app/config.py
+++ b/src/backend/app/config.py
@@ -266,12 +266,16 @@ def configure_s3_download_root(cls, v: Optional[str], info: ValidationInfo) -> s
 
         # Containerised S3
         else:
-            fmtm_domain = info.data.get("FMTM_DOMAIN")
             # Local dev
-            if info.data.get("DEBUG"):
-                dev_port = info.data.get("FMTM_DEV_PORT")
-                return f"http://s3.{fmtm_domain}:{dev_port}"
-            return f"https://s3.{fmtm_domain}"
+            dev_port = info.data.get("FMTM_DEV_PORT")
+            if dev_port:
+                # NOTE This allows us to access S3 data during manual testing
+                # in our web browser, from a domain like: http://s3.fmtm.localhost
+                return f"http://s3.{info.data.get("FMTM_DOMAIN")}:{dev_port}"
+            # return f"https://s3.{fmtm_domain}"
+            # NOTE this allows download via s3:9000 for automated tests,
+            # where the FMTM_DEV_PORT variable is not set
+            return info.data.get("S3_ENDPOINT")
 
     RAW_DATA_API_URL: HttpUrlStr = "https://api-prod.raw-data.hotosm.org/v1"
     RAW_DATA_API_AUTH_TOKEN: Optional[SecretStr] = None
diff --git a/src/backend/tests/conftest.py b/src/backend/tests/conftest.py
index 391fa1affb..3afc12fa33 100644
--- a/src/backend/tests/conftest.py
+++ b/src/backend/tests/conftest.py
@@ -248,11 +248,8 @@ async def odk_project(db, client, project, tasks):
         data_extracts,
     )
 
-    internal_file_path = (
-        f"{settings.S3_ENDPOINT}"
-        f"{data_extract_s3_path.split(settings.FMTM_DEV_PORT)[1]}"
-    )
-    response = requests.head(internal_file_path, allow_redirects=True)
+    # internal_s3_url = f"{settings.S3_ENDPOINT}{urlparse(data_extract_s3_path).path}"
+    response = requests.head(data_extract_s3_path, allow_redirects=True)
     assert response.status_code < 400
 
     xlsform_file = Path(f"{test_data_path}/buildings.xls")
diff --git a/src/backend/tests/test_projects_routes.py b/src/backend/tests/test_projects_routes.py
index 9c836477ce..8d2226ae2e 100644
--- a/src/backend/tests/test_projects_routes.py
+++ b/src/backend/tests/test_projects_routes.py
@@ -359,12 +359,7 @@ async def test_generate_project_files(db, client, project):
         data_extracts,
     )
     assert data_extract_s3_path is not None
-    # Test url, but first sub localhost url with docker network for backend connection
-    internal_file_path = (
-        f"{settings.S3_ENDPOINT}"
-        f"{data_extract_s3_path.split(settings.FMTM_DEV_PORT)[1]}"
-    )
-    response = requests.head(internal_file_path, allow_redirects=True)
+    response = requests.head(data_extract_s3_path, allow_redirects=True)
     assert response.status_code < 400
 
     # Get custom XLSForm path