diff --git a/agent/canvas.py b/agent/canvas.py
index 2dfeb63e6..c8b6f9e38 100644
--- a/agent/canvas.py
+++ b/agent/canvas.py
@@ -13,7 +13,6 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
-import base64
 import json
 import logging
 import re
diff --git a/rag/nlp/__init__.py b/rag/nlp/__init__.py
index cc679bc53..334c63645 100644
--- a/rag/nlp/__init__.py
+++ b/rag/nlp/__init__.py
@@ -266,7 +266,7 @@ def is_chinese(text):
 
 def tokenize(d, txt, eng):
     d["content_with_weight"] = txt
-    t = re.sub(r"</?(table|td|caption|tr|th)( [^<>]{0,12})?>", " ", t)
+    t = re.sub(r"</?(table|td|caption|tr|th)( [^<>]{0,12})?>", " ", txt)
     d["content_ltks"] = rag_tokenizer.tokenize(t)
     d["content_sm_ltks"] = rag_tokenizer.fine_grained_tokenize(d["content_ltks"])