diff --git a/src/serial.rs b/src/serial.rs
index 60a2b9d..979c3f8 100644
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -134,7 +134,7 @@ impl SerialInterface {
     }
 
     pub fn recv_bytes(&mut self) -> Result<Vec<u8>> {
-        let retry_counter = 0;
+        let mut retry_counter = 0;
 
         let packet_bounds: PacketBounds;
         let mut buffer: Vec<u8>;
@@ -154,6 +154,7 @@ impl SerialInterface {
                 break;
             }
 
+            retry_counter += 1;
             std::thread::sleep(std::time::Duration::from_millis(10));
         }