diff --git a/platform/cc2538dk/contiki-conf.h b/platform/cc2538dk/contiki-conf.h
index 34a7f1673..380288f02 100644
--- a/platform/cc2538dk/contiki-conf.h
+++ b/platform/cc2538dk/contiki-conf.h
@@ -40,6 +40,12 @@ typedef uint32_t rtimer_clock_t;
 #define RTIMER_CLOCK_LT(a,b)     ((int32_t)((a)-(b)) < 0)
 /** @} */
 /*---------------------------------------------------------------------------*/
+#define SYS_CTRL_CONF_OSC32K_USE_XTAL	1
+
+#define RADIO_DELAY_BEFORE_TX     ((unsigned)US_TO_RTIMERTICKS(300))
+#define RADIO_DELAY_BEFORE_RX     ((unsigned)US_TO_RTIMERTICKS(100))
+#define RADIO_DELAY_BEFORE_DETECT 0
+/*---------------------------------------------------------------------------*/
 /**
  * \name Serial Boot Loader Backdoor configuration
  *