diff --git a/boards/airfy-beacon/include/periph_conf.h b/boards/airfy-beacon/include/periph_conf.h
index 198b85e99b..3c03484e82 100644
--- a/boards/airfy-beacon/include/periph_conf.h
+++ b/boards/airfy-beacon/include/periph_conf.h
@@ -93,9 +93,9 @@
 #define RTT_NUMOF           (1U)
 #define RTT_IRQ_PRIO        1
 
-#define RTT_DEV             NRF_RTC0
-#define RTT_IRQ             RTC0_IRQn
-#define RTT_ISR             isr_rtc0
+#define RTT_DEV             NRF_RTC1
+#define RTT_IRQ             RTC1_IRQn
+#define RTT_ISR             isr_rtc1
 #define RTT_MAX_VALUE       (0xffffff)
 #define RTT_FREQUENCY       (10)            /* in Hz */
 #define RTT_PRESCALER       (3275U)         /* run with 10 Hz */
diff --git a/boards/pca10000/include/periph_conf.h b/boards/pca10000/include/periph_conf.h
index c1feaabc00..6c6ecdf554 100644
--- a/boards/pca10000/include/periph_conf.h
+++ b/boards/pca10000/include/periph_conf.h
@@ -80,9 +80,9 @@ extern "C" {
 #define RTT_NUMOF           (1U)
 #define RTT_IRQ_PRIO        1
 
-#define RTT_DEV             NRF_RTC0
-#define RTT_IRQ             RTC0_IRQn
-#define RTT_ISR             isr_rtc0
+#define RTT_DEV             NRF_RTC1
+#define RTT_IRQ             RTC1_IRQn
+#define RTT_ISR             isr_rtc1
 #define RTT_MAX_VALUE       (0xffffff)
 #define RTT_FREQUENCY       (10)            /* in Hz */
 #define RTT_PRESCALER       (3275U)         /* run with 10 Hz */
diff --git a/boards/pca10005/include/periph_conf.h b/boards/pca10005/include/periph_conf.h
index 3548e0a964..0a8923622f 100644
--- a/boards/pca10005/include/periph_conf.h
+++ b/boards/pca10005/include/periph_conf.h
@@ -93,9 +93,9 @@ extern "C" {
 #define RTT_NUMOF           (1U)
 #define RTT_IRQ_PRIO        1
 
-#define RTT_DEV             NRF_RTC0
-#define RTT_IRQ             RTC0_IRQn
-#define RTT_ISR             isr_rtc0
+#define RTT_DEV             NRF_RTC1
+#define RTT_IRQ             RTC1_IRQn
+#define RTT_ISR             isr_rtc1
 #define RTT_MAX_VALUE       (0xffffff)
 #define RTT_FREQUENCY       (10)            /* in Hz */
 #define RTT_PRESCALER       (3275U)         /* run with 10 Hz */
diff --git a/boards/yunjia-nrf51822/include/periph_conf.h b/boards/yunjia-nrf51822/include/periph_conf.h
index f37ef58e57..f9665c7529 100644
--- a/boards/yunjia-nrf51822/include/periph_conf.h
+++ b/boards/yunjia-nrf51822/include/periph_conf.h
@@ -91,9 +91,9 @@ extern "C" {
 #define RTT_NUMOF           (1U)
 #define RTT_IRQ_PRIO        1
 
-#define RTT_DEV             NRF_RTC0
-#define RTT_IRQ             RTC0_IRQn
-#define RTT_ISR             isr_rtc0
+#define RTT_DEV             NRF_RTC1
+#define RTT_IRQ             RTC1_IRQn
+#define RTT_ISR             isr_rtc1
 #define RTT_MAX_VALUE       (0xffffff)
 #define RTT_FREQUENCY       (10)            /* in Hz */
 #define RTT_PRESCALER       (3275U)         /* run with 10 Hz */