diff --git a/platform/esb/contiki-conf.h b/platform/esb/contiki-conf.h
index 5fe7938a2..01b9a98ca 100644
--- a/platform/esb/contiki-conf.h
+++ b/platform/esb/contiki-conf.h
@@ -1,6 +1,8 @@
 #ifndef __CONTIKI_CONF_H__
 #define __CONTIKI_CONF_H__
 
+#define IRQ_PORT1_VECTOR 1
+
 #define IRQ_PORT1 0x01
 #define IRQ_PORT2 0x02
 #define IRQ_ADC   0x03