diff --git a/libs/weaviate/langchain_weaviate/vectorstores.py b/libs/weaviate/langchain_weaviate/vectorstores.py
index 43d1f8f..29fa854 100644
--- a/libs/weaviate/langchain_weaviate/vectorstores.py
+++ b/libs/weaviate/langchain_weaviate/vectorstores.py
@@ -428,7 +428,7 @@ def from_texts(
         metadatas: Optional[List[dict]] = None,
         *,
         tenant: Optional[str] = None,
-        client: weaviate.WeaviateClient = None,
+        client: Optional[weaviate.WeaviateClient] = None,
         index_name: Optional[str] = None,
         text_key: str = "text",
         relevance_score_fn: Optional[
@@ -474,6 +474,9 @@ def from_texts(
 
         attributes = list(metadatas[0].keys()) if metadatas else None
 
+        if client is None:
+            raise ValueError("client must be an instance of WeaviateClient")
+
         weaviate_vector_store = cls(
             client,
             index_name,
diff --git a/libs/weaviate/tests/unit_tests/test_vectorstores_unit.py b/libs/weaviate/tests/unit_tests/test_vectorstores_unit.py
index 281ce16..9f32fa0 100644
--- a/libs/weaviate/tests/unit_tests/test_vectorstores_unit.py
+++ b/libs/weaviate/tests/unit_tests/test_vectorstores_unit.py
@@ -5,6 +5,7 @@
 import pytest
 
 from langchain_weaviate.vectorstores import (
+    WeaviateVectorStore,
     _default_score_normalizer,
     _json_serializable,
 )
@@ -29,3 +30,12 @@ def test_json_serializable(
     expected_result: Union[str, int, None],
 ) -> None:
     assert _json_serializable(value) == expected_result
+
+
+def test_from_texts_raises_value_error_when_client_is_none():
+    with pytest.raises(
+        ValueError, match="client must be an instance of WeaviateClient"
+    ):
+        WeaviateVectorStore.from_texts(
+            texts=["sample text"], embedding=None, client=None
+        )