diff --git a/lib/kiss/kiss_serial.rb b/lib/kiss/kiss_serial.rb
index e14957b20d1a45f89a5655f01c0a782304ade05d..729cf0df888eb8aee2eef74ca283f86dfce87a67 100644
--- a/lib/kiss/kiss_serial.rb
+++ b/lib/kiss/kiss_serial.rb
@@ -31,7 +31,7 @@ module Kiss
         def read_interface
             read_data = @serial.read(@read_bytes)
             if read_data
-                return read_data.map { |c| c.ord }
+                return read_data.chars.map { |c| c.ord }
             else
                 return nil
             end