diff --git a/ckanext/charts/fetchers.py b/ckanext/charts/fetchers.py
index 1f8c806..5ea8ba0 100644
--- a/ckanext/charts/fetchers.py
+++ b/ckanext/charts/fetchers.py
@@ -71,11 +71,7 @@ def fetch_data(self) -> pd.DataFrame:
                 .select_from(sa.table(self.resource_id))
                 .limit(self.limit),
                 get_read_engine(),
-            )
-
-            existing_columns = {col for col in {'_id', '_full_text'} if col in df.columns}
-            if existing_columns:
-                df = df.drop(columns=existing_columns)
+            ).drop(columns=["_id", "_full_text"], errors='ignore')
 
             if "date_time" in df.columns:
                 try: