diff --git a/cpu/cc2430/8051def.h b/cpu/cc2430/8051def.h
index a7327ed92..3201cba6e 100644
--- a/cpu/cc2430/8051def.h
+++ b/cpu/cc2430/8051def.h
@@ -45,6 +45,8 @@ typedef unsigned short uip_stats_t;
 /* Time type. */
 typedef unsigned short clock_time_t;
 #define MAX_TICKS (~((clock_time_t)0) / 2)
+/* Defines tick counts for a second. */
+#define CLOCK_CONF_SECOND   128
 
 /* Compiler configurations */
 #define CCIF
diff --git a/cpu/cc253x/8051def.h b/cpu/cc253x/8051def.h
index 7ac0b84ef..e19fd8d31 100644
--- a/cpu/cc253x/8051def.h
+++ b/cpu/cc253x/8051def.h
@@ -1,7 +1,7 @@
 /*
  * \file
  *	This file contains a set of configuration for using SDCC as a compiler.
- *	Modified from z80 port for cc2430 port.
+ *	This is based on the cc2430 file (which in turn is based on the z80 one)
  *
  * \author
  *	 Takahide Matsutsuka <markn@markn.org> (Original)
@@ -42,6 +42,12 @@
 /* Generic types. */
 typedef unsigned short uip_stats_t;
 
+/* Time type. */
+typedef unsigned short clock_time_t;
+#define MAX_TICKS (~((clock_time_t)0) / 2)
+/* Defines tick counts for a second. */
+#define CLOCK_CONF_SECOND   128
+
 /* Compiler configurations */
 #define CCIF
 #define CLIF
diff --git a/platform/cc2530dk/contiki-conf.h b/platform/cc2530dk/contiki-conf.h
index 4eae96016..bae8c34ad 100644
--- a/platform/cc2530dk/contiki-conf.h
+++ b/platform/cc2530dk/contiki-conf.h
@@ -10,12 +10,6 @@
 #include "project-conf.h"
 #endif /* PROJECT_CONF_H */
 
-/* Time type. */
-typedef unsigned short clock_time_t;
-
-/* Defines tick counts for a second. */
-#define CLOCK_CONF_SECOND		128
-
 /* Energest Module */
 #ifndef ENERGEST_CONF_ON
 #define ENERGEST_CONF_ON      0
diff --git a/platform/sensinode/contiki-conf.h b/platform/sensinode/contiki-conf.h
index e40f70b8c..3148605de 100644
--- a/platform/sensinode/contiki-conf.h
+++ b/platform/sensinode/contiki-conf.h
@@ -10,9 +10,6 @@
 #include "project-conf.h"
 #endif /* PROJECT_CONF_H */
 
-/* Defines tick counts for a second. */
-#define CLOCK_CONF_SECOND		128
-
 /* The clock ISR is stack-hungry and may cause crashes.
  * Define this as 0 if you are suffering from frequent stack overflows */
 #ifndef CLOCK_CONF_ACCURATE