diff --git a/backend/src/db/notifications.rs b/backend/src/db/notifications.rs
index 80e7fdf..892ec95 100644
--- a/backend/src/db/notifications.rs
+++ b/backend/src/db/notifications.rs
@@ -108,6 +108,21 @@ pub fn mark_as_new(id: i64) -> Result<(), DbError> {
     }
 }
 
+pub fn mark_all_as_old() -> Result<(), DbError> {
+    let conn = db::get_db_connection();
+
+    match conn.execute("UPDATE notifications SET is_new=0 WHERE is_new=1", []) {
+        Ok(_) => {
+            debug!("All notifications flagged as old");
+            Ok(())
+        }
+        Err(error) => {
+            error!("Error marking all notifications as old: {error}");
+            Err(DbError::from(error))
+        }
+    }
+}
+
 pub fn read(id: i64) -> Option<Notification> {
     let conn = db::get_db_connection();
 
@@ -207,6 +222,48 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn test_mark_all_as_old() {
+        tests_common::setup().await;
+
+        // Insert two new notifications
+        let id1 = insert(Notification::new(
+            Utc::now(),
+            NotificationType::Other,
+            "New notification 1".to_string(),
+            "Body 1".to_string(),
+            true,
+        ))
+        .unwrap();
+
+        let id2 = insert(Notification::new(
+            Utc::now(),
+            NotificationType::Other,
+            "New notification 2".to_string(),
+            "Body 2".to_string(),
+            true,
+        ))
+        .unwrap();
+
+        // Mark all as old
+        mark_all_as_old().unwrap();
+
+        // Both should now have is_new=false
+        assert!(
+            !read(id1).unwrap().is_new,
+            "Notification id={id1} should have is_new=0 after mark_all_as_old"
+        );
+        assert!(
+            !read(id2).unwrap().is_new,
+            "Notification id={id2} should have is_new=0 after mark_all_as_old"
+        );
+
+        // Restore seeded test notifications so other tests are not affected
+        mark_as_new(1).unwrap();
+        mark_as_new(3).unwrap();
+        mark_as_new(5).unwrap();
+    }
+
     #[tokio::test]
     async fn test_insert() {
         tests_common::setup().await;
diff --git a/backend/src/web_server.rs b/backend/src/web_server.rs
index 8a95024..9b1ee09 100644
--- a/backend/src/web_server.rs
+++ b/backend/src/web_server.rs
@@ -33,6 +33,10 @@ pub async fn serve() -> Result<(), Box<dyn Error>> {
         .route("/api/devices/{mac_address}", delete(devices::unregister))
         .route("/api/devices/{mac_address}", get(devices::read))
         .route("/api/notifications", get(notifications::list))
+        .route(
+            "/api/notifications/mark_all_as_old",
+            post(notifications::mark_all_as_old),
+        )
         .route("/api/notifications/{id}", get(notifications::read))
         .route(
             "/api/notifications/{id}/read_without_flagging",
diff --git a/backend/src/web_server/notifications.rs b/backend/src/web_server/notifications.rs
index 73f77df..f021f17 100644
--- a/backend/src/web_server/notifications.rs
+++ b/backend/src/web_server/notifications.rs
@@ -45,6 +45,19 @@ pub async fn mark_as_new(Path(id): Path<i64>) -> impl IntoResponse {
     }
 }
 
+pub async fn mark_all_as_old() -> impl IntoResponse {
+    match db::notifications::mark_all_as_old() {
+        Ok(_) => (StatusCode::OK, "All notifications marked as old"),
+        Err(err) => {
+            error!("Error marking all notifications as old: {}", err);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "Error updating notifications in the server, check your logs",
+            )
+        }
+    }
+}
+
 pub async fn list(
     Query(params): Query<HashMap<String, String>>,
 ) -> Result<Json<Vec<Notification>>, StatusCode> {