diff --git a/arch/arm/src/stm32l4/stm32l4_freerun.c b/arch/arm/src/stm32l4/stm32l4_freerun.c
index a11df0ba0ee..6ffda5ac21f 100644
--- a/arch/arm/src/stm32l4/stm32l4_freerun.c
+++ b/arch/arm/src/stm32l4/stm32l4_freerun.c
@@ -1,4 +1,4 @@
-s/****************************************************************************
+/****************************************************************************
  * arch/arm/src/stm32l4/stm32l4_freerun.c
  *
  *   Copyright (C) 2016 Gregory Nutt. All rights reserved.