diff --git a/sm1-html-2-json5.py b/sm1-html-2-json5.py
index bc2341d..9cba830 100644
--- a/sm1-html-2-json5.py
+++ b/sm1-html-2-json5.py
@@ -273,7 +273,7 @@ def extract_data(html):
 					)
 					if td:
 						columns.append(
-							f"{table_control}-{th.get_text(strip=True)}"
+							f"{table_control}_{th.get_text(strip=True)}"
 						)  # Format as desired
 
 			records.append(