diff --git a/scripts/pylib/twister/twisterlib/handlers.py b/scripts/pylib/twister/twisterlib/handlers.py
index e14c86719a7..5dd4340bc5e 100755
--- a/scripts/pylib/twister/twisterlib/handlers.py
+++ b/scripts/pylib/twister/twisterlib/handlers.py
@@ -422,7 +422,7 @@ def monitor_serial(self, ser, halt_event, harness):
             # is available yet.
             if serial_line:
                 # can be more lines in serial_line so split them before handling
-                for sl in serial_line.decode('utf-8', 'ignore').splitlines():
+                for sl in serial_line.decode('utf-8', 'ignore').splitlines(keepends=True):
                     log_out_fp.write(strip_ansi_sequences(sl).encode('utf-8'))
                     log_out_fp.flush()
                     if sl := sl.strip():