diff --git a/tests/kernel/test_tickless/src/timestamps.c b/tests/kernel/test_tickless/src/timestamps.c
index ff8bac1da06..1ede27e9341 100644
--- a/tests/kernel/test_tickless/src/timestamps.c
+++ b/tests/kernel/test_tickless/src/timestamps.c
@@ -258,7 +258,7 @@ void _TimestampClose(void)
 void _TimestampOpen(void)
 {
 	/* enable RTT clock from PMC */
-	__PMC->pcer0 = (1 << PID_RTT);
+	soc_pmc_peripheral_enable(ID_RTT);
 
 	/* Reset RTT and set prescaler to 1 */
 	_TIMESTAMP_MODE = (1 << 18) | (1 << 0);
@@ -301,7 +301,7 @@ u32_t _TimestampRead(void)
 void _TimestampClose(void)
 {
 	/* disable RTT clock from PMC */
-	__PMC->pcdr0 = (1 << PID_RTT);
+	soc_pmc_peripheral_disable(ID_RTT);
 }
 
 #else