diff --git a/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/i2c_api.c b/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/i2c_api.c
index 9e0408fcf1..3eb27743ec 100644
--- a/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/i2c_api.c
+++ b/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/i2c_api.c
@@ -187,6 +187,7 @@ void i2c_frequency(i2c_t *obj, int hz) {
     uint8_t i, j;
     // bus clk
     uint32_t PCLK = 23986176u;
+    uint32_t pulse;
 
     // we look for the values that minimize the error
 
diff --git a/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/serial_api.c b/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/serial_api.c
index 1cd52eb081..8f8c3ab0a8 100644
--- a/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/serial_api.c
+++ b/libraries/mbed/targets/hal/Freescale/TARGET_KL05Z/serial_api.c
@@ -24,7 +24,7 @@
 #include "pinmap.h"
 #include "error.h"
 
-#define UART_CLOCK_HZ 23986176u
+#define UART_CLOCK_HZ 47972352u
 
 static const PinMap PinMap_UART_TX[] = {
     {PTB1, UART_0, 2},