diff --git a/examples/lightrag_hf_demo.py b/examples/lightrag_hf_demo.py
index 87312307..91033e50 100644
--- a/examples/lightrag_hf_demo.py
+++ b/examples/lightrag_hf_demo.py
@@ -30,7 +30,7 @@ rag = LightRAG(
 )
 
 
-with open("./book.txt") as f:
+with open("./book.txt", "r", encoding="utf-8") as f:
     rag.insert(f.read())
 
 # Perform naive search
diff --git a/examples/lightrag_ollama_demo.py b/examples/lightrag_ollama_demo.py
index c61b71c0..98f1521c 100644
--- a/examples/lightrag_ollama_demo.py
+++ b/examples/lightrag_ollama_demo.py
@@ -21,7 +21,7 @@ rag = LightRAG(
 )
 
 
-with open("./book.txt") as f:
+with open("./book.txt", "r", encoding="utf-8") as f:
     rag.insert(f.read())
 
 # Perform naive search
diff --git a/examples/lightrag_openai_compatible_demo.py b/examples/lightrag_openai_compatible_demo.py
index fbad1190..aae56821 100644
--- a/examples/lightrag_openai_compatible_demo.py
+++ b/examples/lightrag_openai_compatible_demo.py
@@ -55,7 +55,7 @@ rag = LightRAG(
 )
 
 
-with open("./book.txt") as f:
+with open("./book.txt", "r", encoding="utf-8") as f:
     rag.insert(f.read())
 
 # Perform naive search
diff --git a/examples/lightrag_openai_demo.py b/examples/lightrag_openai_demo.py
index a6e7f3b2..29bc75ca 100644
--- a/examples/lightrag_openai_demo.py
+++ b/examples/lightrag_openai_demo.py
@@ -15,7 +15,7 @@ rag = LightRAG(
 )
 
 
-with open("./book.txt") as f:
+with open("./book.txt", "r", encoding="utf-8") as f:
     rag.insert(f.read())
 
 # Perform naive search