diff --git a/boards/chronos/include/board.h b/boards/chronos/include/board.h
index f1dad0cdfc..398875dc94 100644
--- a/boards/chronos/include/board.h
+++ b/boards/chronos/include/board.h
@@ -29,6 +29,8 @@
 #endif
 
 #define MSP430_INITIAL_CPU_SPEED    7372800uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             1
 #define MSP430_HAS_EXTERNAL_CRYSTAL 1
 
diff --git a/boards/msb-430/include/board.h b/boards/msb-430/include/board.h
index cdfd7b2545..661bf4b471 100644
--- a/boards/msb-430/include/board.h
+++ b/boards/msb-430/include/board.h
@@ -52,7 +52,9 @@ and the mailinglist (subscription via web site)
 #endif
 
 //MSB430 core
-#define MSP430_INITIAL_CPU_SPEED 2457600uL
+#define MSP430_INITIAL_CPU_SPEED    2457600uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             1
 #define MSP430_HAS_EXTERNAL_CRYSTAL 0
 
diff --git a/boards/msb-430h/include/board.h b/boards/msb-430h/include/board.h
index f622eea909..29bc123a8a 100644
--- a/boards/msb-430h/include/board.h
+++ b/boards/msb-430h/include/board.h
@@ -46,6 +46,8 @@ and the mailinglist (subscription via web site)
 
 //MSB430 core
 #define MSP430_INITIAL_CPU_SPEED    7372800uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             1
 #define MSP430_HAS_EXTERNAL_CRYSTAL 1
 
diff --git a/boards/telosb/include/board.h b/boards/telosb/include/board.h
index 3fd94ca82f..9e94a5d3cb 100644
--- a/boards/telosb/include/board.h
+++ b/boards/telosb/include/board.h
@@ -32,6 +32,8 @@
 
 //MSB430 core
 #define MSP430_INITIAL_CPU_SPEED    8000000uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             0
 #define MSP430_HAS_EXTERNAL_CRYSTAL 1
 
diff --git a/boards/wsn430-v1_3b/include/board.h b/boards/wsn430-v1_3b/include/board.h
index 05b639ba54..6ffa51610d 100644
--- a/boards/wsn430-v1_3b/include/board.h
+++ b/boards/wsn430-v1_3b/include/board.h
@@ -35,6 +35,8 @@
 
 //MSB430 core
 #define MSP430_INITIAL_CPU_SPEED    800000uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             0
 #define MSP430_HAS_EXTERNAL_CRYSTAL 1
 
diff --git a/boards/wsn430-v1_4/include/board.h b/boards/wsn430-v1_4/include/board.h
index ea0452b904..c7b18f8475 100644
--- a/boards/wsn430-v1_4/include/board.h
+++ b/boards/wsn430-v1_4/include/board.h
@@ -35,6 +35,8 @@
 
 //MSB430 core
 #define MSP430_INITIAL_CPU_SPEED    800000uL
+#define F_CPU                       MSP430_INITIAL_CPU_SPEED
+#define F_RC_OSCILLATOR             32768
 #define MSP430_HAS_DCOR             0
 #define MSP430_HAS_EXTERNAL_CRYSTAL 1
 
diff --git a/cpu/msp430-common/include/cpu.h b/cpu/msp430-common/include/cpu.h
index a8835f71b2..62387a4f82 100644
--- a/cpu/msp430-common/include/cpu.h
+++ b/cpu/msp430-common/include/cpu.h
@@ -36,9 +36,9 @@ See the file LICENSE in the top level directory for more details.
 
 #define WORDSIZE 16
 
-/* CPU speed */
-#define F_CPU               (2457600ul)
-#define F_RC_OSCILLATOR     (32768) ///< Frequency of internal RC oscillator
+/* CPU speed, to be defined in board.h */
+//#define F_CPU               (2457600ul)
+//#define F_RC_OSCILLATOR     (32768) ///< Frequency of internal RC oscillator
 
 extern volatile int __inISR;
 extern char __isr_stack[MSP430_ISR_STACK_SIZE];