diff --git a/recipes-connectivity/sim-config/files/sim-config.py b/recipes-connectivity/sim-config/files/sim-config.py
index 325a71e..88de4c6 100755
--- a/recipes-connectivity/sim-config/files/sim-config.py
+++ b/recipes-connectivity/sim-config/files/sim-config.py
@@ -28,7 +28,7 @@ def reset_modem():
     time.sleep(2)
     write_to_file(GPIO_PATH + 'gpio' + GPIO_SIM_RST + '/value', '0')
     # Wait until modem rebooted
-    while os.path.exists('dev/ttyACM0'):
+    while os.path.exists('/dev/ttyACM0'):
         time.sleep(1)
     while not os.path.exists('/dev/ttyACM0'):
         time.sleep(1)