diff --git a/pandasai/helpers/sql_sanitizer.py b/pandasai/helpers/sql_sanitizer.py
index 1787921e9..089761eaa 100644
--- a/pandasai/helpers/sql_sanitizer.py
+++ b/pandasai/helpers/sql_sanitizer.py
@@ -99,7 +99,7 @@ def is_sql_query_safe(query: str, dialect: str = "postgres") -> bool:
         return False
 
 
-def is_sql_query(query):
+def is_sql_query(query: str) -> bool:
     # Define SQL patterns with context to avoid standalone keyword matches
     sql_patterns = [
         r"\bSELECT\b.*\bFROM\b",
diff --git a/pandasai/query_builders/sql_parser.py b/pandasai/query_builders/sql_parser.py
index 9a70dc442..1b1c2f586 100644
--- a/pandasai/query_builders/sql_parser.py
+++ b/pandasai/query_builders/sql_parser.py
@@ -57,7 +57,7 @@ def transform_node(node):
         return transformed.sql(pretty=True)
 
     @staticmethod
-    def transpile_sql_dialect(query: str, to_dialect, from_dialect=None):
+    def transpile_sql_dialect(query: str, to_dialect: str, from_dialect: Optional[str] = None):
         placeholder = "___PLACEHOLDER___"
         query = query.replace("%s", placeholder)
         query = (