diff --git a/nixos/lib/test-driver/test-driver.py b/nixos/lib/test-driver/test-driver.py
index cec9cdf7528..bd52233964b 100644
--- a/nixos/lib/test-driver/test-driver.py
+++ b/nixos/lib/test-driver/test-driver.py
@@ -601,7 +601,7 @@ class Machine:
             stdin=subprocess.DEVNULL,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
-            shell=False,
+            shell=True,
             cwd=self.state_dir,
             env=environment,
         )
@@ -610,7 +610,7 @@ class Machine:
 
         def process_serial_output():
             for line in self.process.stdout:
-                line = line.decode().replace("\r", "").rstrip()
+                line = line.decode("unicode_escape").replace("\r", "").rstrip()
                 eprint("{} # {}".format(self.name, line))
                 self.logger.enqueue({"msg": line, "machine": self.name})