diff --git a/src/afterfact.rs b/src/afterfact.rs
index 3ea91a20..d0bca5eb 100644
--- a/src/afterfact.rs
+++ b/src/afterfact.rs
@@ -251,12 +251,18 @@ fn emit_csv<W: std::io::Write>(
                     .record_information
                     .as_ref()
                     .map(|recinfo| _format_cellpos(recinfo, ColPos::Last));
-                let details = detect_info
+                let ctr_char_exclude_details = detect_info
                     .detail
                     .chars()
                     .filter(|&c| !c.is_control())
                     .collect::<String>();
 
+                let details = if ctr_char_exclude_details.is_empty() {
+                    "-".to_string()
+                } else {
+                    ctr_char_exclude_details
+                };
+
                 let dispformat: _ = DisplayFormat {
                     timestamp: &_format_cellpos(&time_str, ColPos::First),
                     level: &_format_cellpos(level_abbr.get(&level).unwrap_or(&level), ColPos::Other),