diff --git a/arch/arm/include/spinlock.h b/arch/arm/include/spinlock.h
index fbd0e424382..44e405e6303 100644
--- a/arch/arm/include/spinlock.h
+++ b/arch/arm/include/spinlock.h
@@ -82,7 +82,7 @@ typedef uint8_t spinlock_t;
  * Name: up_testset
  *
  * Description:
- *   Perform and atomic test and set operation on the provided spinlock.
+ *   Perform an atomic test and set operation on the provided spinlock.
  *
  *   This function must be provided via the architecture-specific logoic.
  *
diff --git a/arch/sim/include/spinlock.h b/arch/sim/include/spinlock.h
index 3c20ffe22af..350bf24b33e 100644
--- a/arch/sim/include/spinlock.h
+++ b/arch/sim/include/spinlock.h
@@ -66,7 +66,7 @@ typedef bool spinlock_t;
  * Name: up_testset
  *
  * Description:
- *   Perform and atomic test and set operation on the provided spinlock.
+ *   Perform an atomic test and set operation on the provided spinlock.
  *
  *   This function must be provided via the architecture-specific logoic.
  *
diff --git a/include/nuttx/spinlock.h b/include/nuttx/spinlock.h
index 544facfef91..c749d9e329d 100644
--- a/include/nuttx/spinlock.h
+++ b/include/nuttx/spinlock.h
@@ -83,7 +83,7 @@ struct spinlock_s
  * Name: up_testset
  *
  * Description:
- *   Perform and atomic test and set operation on the provided spinlock.
+ *   Perform an atomic test and set operation on the provided spinlock.
  *
  *   This function must be provided via the architecture-specific logoic.
  *