diff --git a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_K20XX/rtc.api.c b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_K20XX/rtc.api.c
index 459c7b691a..d7dd1c8050 100644
--- a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_K20XX/rtc.api.c
+++ b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_K20XX/rtc.api.c
@@ -29,9 +29,15 @@ static void init(void) {
 
 void rtc_init(void) {
     init();
-
+    
     // Enable the oscillator
+#if defined (TARGET_K20D50M)
     RTC->CR |= RTC_CR_OSCE_MASK;
+#else
+    // Teensy3.1 requires 20pF MCU loading capacitors for 32KHz RTC oscillator
+    /* RTC->CR: SC2P=0,SC4P=1,SC8P=0,SC16P=1,CLKO=0,OSCE=1,UM=0,SUP=0,SPE=0,SWR=0 */
+    RTC->CR |= RTC_CR_OSCE_MASK |RTC_CR_SC16P_MASK | RTC_CR_SC4P_MASK; 
+#endif
 
     //Configure the TSR. default value: 1
     RTC->TSR = 1;