diff --git a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F030R8/us_ticker.c b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F030R8/us_ticker.c
index d340a526b2..3882b0003e 100644
--- a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F030R8/us_ticker.c
+++ b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F030R8/us_ticker.c
@@ -37,8 +37,8 @@
 
 static int      us_ticker_inited = 0;
 static volatile uint32_t SlaveCounter = 0;
-static uint32_t oc_int_part = 0;
-static uint16_t oc_rem_part = 0;
+static volatile uint32_t oc_int_part = 0;
+static volatile uint16_t oc_rem_part = 0;
 
 void set_compare(uint16_t count) {
     // Set new output compare value
diff --git a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/us_ticker.c b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/us_ticker.c
index 07bee5d67c..121cd6aaf9 100644
--- a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/us_ticker.c
+++ b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/us_ticker.c
@@ -37,8 +37,8 @@
 
 static int      us_ticker_inited = 0;
 static volatile uint32_t SlaveCounter = 0;
-static uint32_t oc_int_part = 0;
-static uint16_t oc_rem_part = 0;
+static volatile uint32_t oc_int_part = 0;
+static volatile uint16_t oc_rem_part = 0;
 
 void set_compare(uint16_t count) {
     // Set new output compare value
diff --git a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F401RE/us_ticker.c b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F401RE/us_ticker.c
index e1088dec9a..671a3eb82d 100644
--- a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F401RE/us_ticker.c
+++ b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_F401RE/us_ticker.c
@@ -40,8 +40,8 @@ static TIM_HandleTypeDef TimMasterHandle;
     
 static int      us_ticker_inited = 0;
 static volatile uint32_t SlaveCounter = 0;
-static uint32_t oc_int_part = 0;
-static uint16_t oc_rem_part = 0;
+static volatile uint32_t oc_int_part = 0;
+static volatile uint16_t oc_rem_part = 0;
 
 void set_compare(uint16_t count) {
     // Set new output compare value
diff --git a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/us_ticker.c b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/us_ticker.c
index 87aa93dd26..0c07dba990 100644
--- a/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/us_ticker.c
+++ b/libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/us_ticker.c
@@ -36,8 +36,8 @@
 
 static int      us_ticker_inited = 0;
 static volatile uint32_t SlaveCounter = 0;
-static uint32_t oc_int_part = 0;
-static uint16_t oc_rem_part = 0;
+static volatile uint32_t oc_int_part = 0;
+static volatile uint16_t oc_rem_part = 0;
 
 void set_compare(uint16_t count) {
     // Set new output compare value
@@ -58,20 +58,19 @@ static void tim_update_oc_irq_handler(void) {
     // Output compare interrupt: used by interrupt system
     if (TIM_GetITStatus(TIM_MST, TIM_IT_CC1) == SET) {
         TIM_ClearITPendingBit(TIM_MST, TIM_IT_CC1);
-    }
-
-    if (oc_rem_part > 0) {
-        set_compare(oc_rem_part); // Finish the remaining time left
-        oc_rem_part = 0;
-    }
-    else {
-        if (oc_int_part > 0) {
-            set_compare(0xFFFF);
-            oc_rem_part = cval; // To finish the counter loop the next time
-            oc_int_part--;
+        if (oc_rem_part > 0) {
+            set_compare(oc_rem_part); // Finish the remaining time left
+            oc_rem_part = 0;
         }
         else {
-            us_ticker_irq_handler();
+            if (oc_int_part > 0) {
+                set_compare(0xFFFF);
+                oc_rem_part = cval; // To finish the counter loop the next time
+                oc_int_part--;
+            }
+            else {
+                us_ticker_irq_handler();
+            }
         }
     }
 }