diff --git a/arch/arm/src/armv7-a/arm_testset.S b/arch/arm/src/armv7-a/arm_testset.S
index 6d6cdcd4acb..e89cbb3adc5 100644
--- a/arch/arm/src/armv7-a/arm_testset.S
+++ b/arch/arm/src/armv7-a/arm_testset.S
@@ -70,7 +70,7 @@
  * 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/arm/src/armv7-m/gnu/up_testset.S b/arch/arm/src/armv7-m/gnu/up_testset.S
index 7dd45eee4db..c1888c56a98 100644
--- a/arch/arm/src/armv7-m/gnu/up_testset.S
+++ b/arch/arm/src/armv7-m/gnu/up_testset.S
@@ -72,7 +72,7 @@
  * 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/arm/src/armv7-m/iar/up_testset.S b/arch/arm/src/armv7-m/iar/up_testset.S
index 9590e576e77..e690aed3de9 100644
--- a/arch/arm/src/armv7-m/iar/up_testset.S
+++ b/arch/arm/src/armv7-m/iar/up_testset.S
@@ -57,7 +57,7 @@
  * 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/arm/src/armv7-r/arm_testset.S b/arch/arm/src/armv7-r/arm_testset.S
index 7cd741fed73..f82837d5fe8 100644
--- a/arch/arm/src/armv7-r/arm_testset.S
+++ b/arch/arm/src/armv7-r/arm_testset.S
@@ -70,7 +70,7 @@
  * 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/src/up_testset.c b/arch/sim/src/up_testset.c
index 30cb64c0ef5..d1b754bca06 100644
--- a/arch/sim/src/up_testset.c
+++ b/arch/sim/src/up_testset.c
@@ -71,7 +71,7 @@ static pthread_mutex_t g_tsmutex = PTHREAD_MUTEX_INITIALIZER;
  * 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/arch.h b/include/nuttx/arch.h
index c1eacf0bd9f..1ef8efe4b18 100644
--- a/include/nuttx/arch.h
+++ b/include/nuttx/arch.h
@@ -1689,7 +1689,7 @@ int up_timer_start(FAR const struct timespec *ts);
  * 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.
  *
  * Input Parameters:
  *   lock - The address of spinlock object.