diff --git a/alws/crud/errata.py b/alws/crud/errata.py
index 8c86de2f1..488b710f2 100644
--- a/alws/crud/errata.py
+++ b/alws/crud/errata.py
@@ -139,6 +139,10 @@ async def get_oval_xml(
         select(models.Platform).where(models.Platform.name == platform_name)
     )
     platform: models.Platform = platform.scalars().first()
+
+    if not platform:
+        return
+
     query = query.filter(models.NewErrataRecord.platform_id == platform.id)
 
     if only_released:
diff --git a/alws/routers/errata.py b/alws/routers/errata.py
index 419744a0d..05fd00924 100644
--- a/alws/routers/errata.py
+++ b/alws/routers/errata.py
@@ -61,7 +61,13 @@ async def get_oval_xml(
     only_released: bool = False,
     db: AsyncSession = Depends(get_db),
 ):
-    return await errata_crud.get_oval_xml(db, platform_name, only_released)
+    records = await errata_crud.get_oval_xml(db, platform_name, only_released)
+    if not records:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"{platform_name} is not a valid platform",
+        )
+    return records
 
 
 @public_router.get("/query/", response_model=errata_schema.ErrataListResponse)