diff --git a/llama_stack/core/store/registry.py b/llama_stack/core/store/registry.py
index 624dbd176..234a994f9 100644
--- a/llama_stack/core/store/registry.py
+++ b/llama_stack/core/store/registry.py
@@ -14,7 +14,10 @@ from llama_stack.core.datatypes import RoutableObjectWithProvider
 from llama_stack.core.utils.config_dirs import DISTRIBS_BASE_DIR
 from llama_stack.log import get_logger
 from llama_stack.providers.utils.kvstore import KVStore, kvstore_impl
-from llama_stack.providers.utils.kvstore.config import KVStoreConfig, SqliteKVStoreConfig
+from llama_stack.providers.utils.kvstore.config import (
+    KVStoreConfig,
+    SqliteKVStoreConfig,
+)
 
 logger = get_logger(__name__, category="core::registry")
 
@@ -98,7 +101,10 @@ class DiskDistributionRegistry(DistributionRegistry):
         existing_obj = await self.get(obj.type, obj.identifier)
         # dont register if the object's providerid already exists
         if existing_obj and existing_obj.provider_id == obj.provider_id:
-            return False
+            raise ValueError(
+                f"Provider '{obj.provider_id}' is already registered."
+                f"Unregister the existing provider first before registering it again."
+            )
 
         await self.kvstore.set(
             KEY_FORMAT.format(type=obj.type, identifier=obj.identifier),
diff --git a/tests/unit/registry/test_registry.py b/tests/unit/registry/test_registry.py
index 4ea4a20b9..e17855b40 100644
--- a/tests/unit/registry/test_registry.py
+++ b/tests/unit/registry/test_registry.py
@@ -125,8 +125,15 @@ async def test_duplicate_provider_registration(cached_disk_dist_registry):
         provider_resource_id="test_vector_db_2",
         provider_id="baz",  # Same provider_id
     )
-    await cached_disk_dist_registry.register(duplicate_vector_db)
 
+    # Now we expect a ValueError to be raised for duplicate registration
+    with pytest.raises(
+        ValueError,
+        match=r"Provider 'baz' is already registered.*Unregister the existing provider first before registering it again.",
+    ):
+        await cached_disk_dist_registry.register(duplicate_vector_db)
+
+    # Verify the original registration is still intact
     result = await cached_disk_dist_registry.get("vector_db", "test_vector_db_2")
     assert result is not None
     assert result.embedding_model == original_vector_db.embedding_model  # Original values preserved
@@ -174,10 +181,14 @@ async def test_parse_registry_values_error_handling(sqlite_kvstore):
     )
 
     await sqlite_kvstore.set(
-        KEY_FORMAT.format(type="vector_db", identifier="valid_vector_db"), valid_db.model_dump_json()
+        KEY_FORMAT.format(type="vector_db", identifier="valid_vector_db"),
+        valid_db.model_dump_json(),
     )
 
-    await sqlite_kvstore.set(KEY_FORMAT.format(type="vector_db", identifier="corrupted_json"), "{not valid json")
+    await sqlite_kvstore.set(
+        KEY_FORMAT.format(type="vector_db", identifier="corrupted_json"),
+        "{not valid json",
+    )
 
     await sqlite_kvstore.set(
         KEY_FORMAT.format(type="vector_db", identifier="missing_fields"),
@@ -212,7 +223,8 @@ async def test_cached_registry_error_handling(sqlite_kvstore):
     )
 
     await sqlite_kvstore.set(
-        KEY_FORMAT.format(type="vector_db", identifier="valid_cached_db"), valid_db.model_dump_json()
+        KEY_FORMAT.format(type="vector_db", identifier="valid_cached_db"),
+        valid_db.model_dump_json(),
     )
 
     await sqlite_kvstore.set(