diff --git a/src/adapters/output/local.rs b/src/adapters/output/local.rs
index e0ad252..017469b 100644
--- a/src/adapters/output/local.rs
+++ b/src/adapters/output/local.rs
@@ -9,7 +9,7 @@ pub async fn write_keys_txt_file(
     file: &mut BufWriter<tokio::fs::File>,
     key: &ApiKey,
 ) -> Result<()> {
-    file.write_all(key.as_str().as_bytes()).await?;
+    file.write_all(format!("{}\n", key.as_str()).as_bytes()).await?;
     Ok(())
 }
 
diff --git a/src/validation.rs b/src/validation.rs
index 9fe6ced..8a12473 100644
--- a/src/validation.rs
+++ b/src/validation.rs
@@ -3,7 +3,7 @@ use async_stream::stream;
 use futures::{pin_mut, stream::StreamExt};
 use reqwest::Client;
 use std::time::Instant;
-use tokio::{fs, sync::mpsc};
+use tokio::{fs, io::AsyncWriteExt, sync::mpsc};
 
 use crate::adapters::write_keys_txt_file;
 use crate::config::KeyCheckerConfig;
@@ -59,6 +59,9 @@ impl ValidationService {
             }
         }
 
+        // Flush the buffer to ensure all data is written to the file
+        buffer_writer.flush().await?;
+
         println!("Total Elapsed Time: {:?}", start_time.elapsed());
         Ok(())
     }