diff --git a/src/main.py b/src/main.py
index 72a99f2..b14f270 100644
--- a/src/main.py
+++ b/src/main.py
@@ -75,6 +75,7 @@ def copy_excel_file(source_path, destination_path, passwords):
         # Create new sheet in destination workbook
         from openpyxl.chartsheet import Chartsheet
         if isinstance(source_sheet, Chartsheet):
+            chartsheet_warning = f"Chartsheet detected in '{os.path.basename(source_path)}' on sheet '{sheet_name}'."
             # For chartsheets, we need to create a worksheet instead
             dest_sheet = dest_wb.create_sheet(title=sheet_name)
             
@@ -179,6 +180,8 @@ def copy_excel_file(source_path, destination_path, passwords):
     logging.info(f"Saved copied file to: {destination_path}")
     dest_wb.close()
     source_wb.close()
+    
+    return chartsheet_warning  # Return the warning message if any chartsheets were found
 
 def remove_all_protection_tags(docx_path, output_path):
     logging.info(f"Processing Word document: {docx_path}")
diff --git a/src/streamlit_app.py b/src/streamlit_app.py
index 399d2c6..2ece62c 100644
--- a/src/streamlit_app.py
+++ b/src/streamlit_app.py
@@ -371,7 +371,9 @@ if input_method == "Upload Files" and uploaded_files and st.button("Process File
                 temp_output_path = f"{temp_input_path}_processed"
                 
                 if file_type == "Excel":
-                    copy_excel_file(temp_input_path, temp_output_path, passwords)
+                    chartsheet_warning = copy_excel_file(temp_input_path, temp_output_path, passwords)
+                    if chartsheet_warning:
+                        st.warning(f"⚠️ {chartsheet_warning} Please check the processed file against the original to ensure data was copied correctly.")
                 else:  # Word
                     remove_all_protection_tags(temp_input_path, temp_output_path)
                 
@@ -455,7 +457,9 @@ elif input_method == "Select Directory" and source_dir and dest_dir and st.butto
                     os.makedirs(os.path.dirname(dest_path), exist_ok=True)
                     
                     if file_type == "Excel":
-                        copy_excel_file(source_path, dest_path, passwords)
+                        chartsheet_warning = copy_excel_file(source_path, dest_path, passwords)
+                        if chartsheet_warning:
+                            st.warning(f"⚠️ {chartsheet_warning} Please check the processed file against the original to ensure data was copied correctly.")
                     else:  # Word
                         remove_all_protection_tags(source_path, dest_path)