diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0b6729a..2e97ce5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Added total hours to the grouped list (thanks to [@Niatross](https://github.com/Niatross))
 - Update of libc:musl to support longarch64 (thanks to [@zhaixiaojuan](https://github.com/zhaixiaojuan))
 - Improved general `--help` output (thanks to [@RossBarnie](https://github.com/RossBarnie))
 
diff --git a/src/data/filter.rs b/src/data/filter.rs
index 5af0de5..8ee4c27 100644
--- a/src/data/filter.rs
+++ b/src/data/filter.rs
@@ -110,11 +110,11 @@ mod tests {
             start: date(2024, 3, 19),
             end: None,
         };
-        return vec![a0, a1, a2, a3, a4];
+        vec![a0, a1, a2, a3, a4]
     }
 
     fn date(year: i32, month: u32, day: u32) -> NaiveDateTime {
         let date = NaiveDate::from_ymd_opt(year, month, day).unwrap();
-        return NaiveDateTime::new(date, chrono::NaiveTime::from_hms_opt(10, 0, 0).unwrap());
+        NaiveDateTime::new(date, chrono::NaiveTime::from_hms_opt(10, 0, 0).unwrap())
     }
 }
diff --git a/src/data/getter.rs b/src/data/getter.rs
index dd7bec2..9823771 100644
--- a/src/data/getter.rs
+++ b/src/data/getter.rs
@@ -99,7 +99,7 @@ pub fn filter_activities<'a>(
         .filter(move |activity| {
             filter
                 .project
-                .map_or(true, |p| WildMatch::new(p).matches(&activity.project))
+                .is_none_or(|p| WildMatch::new(p).matches(&activity.project))
         })
         .collect()
 }
diff --git a/src/view/list.rs b/src/view/list.rs
index 1eb8dda..d9aa30e 100644
--- a/src/view/list.rs
+++ b/src/view/list.rs
@@ -5,6 +5,7 @@ use std::collections::BTreeMap;
 use crate::conf;
 use crate::data::activity;
 use crate::view::format_util;
+use crate::view::report;
 use crate::view::table;
 
 // displays a table with activities
@@ -73,7 +74,17 @@ fn create_activities_group(title: &str, activities: &[&activity::Activity]) -> t
         .iter()
         .map(|a| get_activity_table_row(a, false))
         .collect();
-    table::Group::new(Some(title.to_string()), rows)
+
+    let total_duration = report::sum_duration(activities);
+
+    table::Group::new(
+        Some(format!(
+            "{}\t{}",
+            title,
+            format_util::format_duration(&total_duration)
+        )),
+        rows,
+    )
 }
 
 // displays a table with running activities (no end time)
@@ -170,7 +181,7 @@ pub fn list_descriptions_and_projects_with_index(
 fn get_activity_table_row(activity: &activity::Activity, with_start_dates: bool) -> table::Row {
     let more_then_one_day = activity
         .end
-        .map_or(false, |end| activity.start.date() != end.date());
+        .is_some_and(|end| activity.start.date() != end.date());
 
     let display_end = activity.end.map_or_else(
         || "-".to_string(),
diff --git a/src/view/report.rs b/src/view/report.rs
index 22c456a..f2757dc 100644
--- a/src/view/report.rs
+++ b/src/view/report.rs
@@ -27,7 +27,7 @@ impl<'a> Report<'a> {
     }
 }
 
-impl<'a> fmt::Display for Report<'a> {
+impl fmt::Display for Report<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut longest_line = get_longest_line(&self.project_map).unwrap_or(0);
         let longest_duration_string = get_longest_duration_string(self).unwrap_or(0);
@@ -61,7 +61,7 @@ pub fn show_activities<'a>(activities: &'a [&'a activity::Activity]) {
     println!("\n{report}");
 }
 
-fn create_project_map<'a>(activities: &'a [&'a activity::Activity]) -> ProjectMap {
+fn create_project_map<'a>(activities: &'a [&'a activity::Activity]) -> ProjectMap<'a> {
     let mut project_map: ProjectMap = BTreeMap::new();
 
     for a in activities {
@@ -79,7 +79,7 @@ fn create_project_map<'a>(activities: &'a [&'a activity::Activity]) -> ProjectMa
     project_map
 }
 
-fn sum_duration(activities: &[&activity::Activity]) -> Duration {
+pub fn sum_duration(activities: &[&activity::Activity]) -> Duration {
     let mut duration = Duration::seconds(0);
 
     for activity in activities {
@@ -172,8 +172,8 @@ fn print_total_duration(
 
 fn group_activities_by_description<'a>(
     activities: &'a [&'a activity::Activity],
-) -> BTreeMap<&str, Vec<&'a activity::Activity>> {
-    let mut activity_map: BTreeMap<&str, Vec<&'a activity::Activity>> = BTreeMap::new();
+) -> BTreeMap<&'a str, Vec<&'a activity::Activity>> {
+    let mut activity_map: BTreeMap<&'a str, Vec<&'a activity::Activity>> = BTreeMap::new();
 
     for a in activities {
         activity_map.entry(&a.description).or_default().push(a);
diff --git a/src/view/status.rs b/src/view/status.rs
index 0272195..24c2dd5 100644
--- a/src/view/status.rs
+++ b/src/view/status.rs
@@ -16,7 +16,7 @@ impl StatusReportWriter for StatusReport {
     }
 }
 
-impl<'a> fmt::Display for StatusReportData<'a> {
+impl fmt::Display for StatusReportData<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let longest_line = 30;
         print_title(f, self.project)?;
@@ -236,7 +236,7 @@ mod tests {
 
     fn clean(a: &str) -> String {
         let st_f = "\u{1b}[0m\u{1b}";
-        let clean_res = a.replace(st_f, "<>");
-        clean_res
+
+        a.replace(st_f, "<>")
     }
 }