diff --git a/cobc/parser.y b/cobc/parser.y
index 84465f2f4..2e6b190eb 100644
--- a/cobc/parser.y
+++ b/cobc/parser.y
@@ -9252,7 +9252,10 @@ report_group_description_entry:
 | level_number error _dot_or_else_end_of_report_group_description
   {
 	/* Free tree associated with level number */
+#if 0 /* works fine without, leads to invalid free otherwise [COB_TREE_DEBUG] */
+	/* Free tree associated with level number */
 	cobc_parse_free ($1);
+#endif
 	yyerrok;
 	check_pic_duplicate = 0;
 	check_duplicate = 0;