diff --git a/cpu/cc253x/dev/clock.c b/cpu/cc253x/dev/clock.c
index 08a32f031..a2d43987b 100644
--- a/cpu/cc253x/dev/clock.c
+++ b/cpu/cc253x/dev/clock.c
@@ -48,7 +48,7 @@
 #define TICK_VAL (32768/128)  /* 256 */
 /*---------------------------------------------------------------------------*/
 #if CLOCK_CONF_STACK_FRIENDLY
-volatile __bit sleep_flag;
+volatile uint8_t sleep_flag;
 #else
 #endif
 /*---------------------------------------------------------------------------*/
diff --git a/platform/cc2530dk/contiki-main.c b/platform/cc2530dk/contiki-main.c
index 512472bd4..a8154e1d1 100644
--- a/platform/cc2530dk/contiki-main.c
+++ b/platform/cc2530dk/contiki-main.c
@@ -40,7 +40,7 @@ PROCESS_NAME(viztool_process);
 #endif
 /*---------------------------------------------------------------------------*/
 #if CLOCK_CONF_STACK_FRIENDLY
-extern volatile __bit sleep_flag;
+extern volatile uint8_t sleep_flag;
 #endif
 /*---------------------------------------------------------------------------*/
 extern rimeaddr_t rimeaddr_node_addr;