diff --git a/configs/fire-stm32v2/include/board.h b/configs/fire-stm32v2/include/board.h
index 9a5d309ab6..acd70933a2 100644
--- a/configs/fire-stm32v2/include/board.h
+++ b/configs/fire-stm32v2/include/board.h
@@ -55,10 +55,19 @@
 
 /* Clocking *************************************************************************/
 
-/* On-board crystal frequency is 8MHz (HSE) */
+/* HSI - 8 MHz RC factory-trimmed
+ * LSI - 40 KHz RC (30-60KHz, uncalibrated)
+ * HSE - On-board crystal frequency is 8MHz
+ * LSE - 32.768 kHz crytal
+ */
 
 #define STM32_BOARD_XTAL        8000000ul
 
+#define STM32_HSI_FREQUENCY     8000000ul
+#define STM32_LSI_FREQUENCY     40000
+#define STM32_HSE_FREQUENCY     STM32_BOARD_XTAL
+#define STM32_LSE_FREQUENCY     32768
+
 /* PLL source is HSE/1, PLL multipler is 9: PLL frequency is 8MHz (XTAL) x 9 = 72MHz */
 
 #define STM32_CFGR_PLLSRC       RCC_CFGR_PLLSRC
diff --git a/configs/olimex-stm32-p107/include/board.h b/configs/olimex-stm32-p107/include/board.h
index ce0c82472f..96051e25c2 100644
--- a/configs/olimex-stm32-p107/include/board.h
+++ b/configs/olimex-stm32-p107/include/board.h
@@ -55,10 +55,19 @@
 
 /* Clocking *************************************************************************/
 
-/* On-board crystal frequency is 25MHz (HSE) */
+/* HSI - 8 MHz RC factory-trimmed
+ * LSI - 40 KHz RC (30-60KHz, uncalibrated)
+ * HSE - On-board crystal frequency is 25MHz
+ * LSE - 32.768 kHz
+ */
 
 #define STM32_BOARD_XTAL        25000000ul
 
+#define STM32_HSI_FREQUENCY     8000000ul
+#define STM32_LSI_FREQUENCY     40000
+#define STM32_HSE_FREQUENCY     STM32_BOARD_XTAL
+#define STM32_LSE_FREQUENCY     32768
+
 /* PLL ouput is 72MHz */
 
 #define STM32_PLL_PREDIV2       RCC_CFGR2_PREDIV2d5   /* 25MHz / 5 => 5MHz */
diff --git a/configs/shenzhou/include/board.h b/configs/shenzhou/include/board.h
index c105d4ab5e..2897ac2198 100644
--- a/configs/shenzhou/include/board.h
+++ b/configs/shenzhou/include/board.h
@@ -55,10 +55,19 @@
 
 /* Clocking *************************************************************************/
 
-/* On-board crystal frequency is 25MHz (HSE) */
+/* HSI - 8 MHz RC factory-trimmed
+ * LSI - 40 KHz RC (30-60KHz, uncalibrated)
+ * HSE - On-board crystal frequency is 25MHz
+ * LSE - 32.768 kHz
+ */
 
 #define STM32_BOARD_XTAL        25000000ul
 
+#define STM32_HSI_FREQUENCY     8000000ul
+#define STM32_LSI_FREQUENCY     40000
+#define STM32_HSE_FREQUENCY     STM32_BOARD_XTAL
+#define STM32_LSE_FREQUENCY     32768
+
 /* PLL ouput is 72MHz */
 
 #define STM32_PLL_PREDIV2       RCC_CFGR2_PREDIV2d5   /* 25MHz / 5 => 5MHz */