diff --git a/examples/stm32/obldc/usart_irq/usart_irq.c b/examples/stm32/obldc/usart_irq/usart_irq.c
index 2d4dd06b..7e5f9719 100644
--- a/examples/stm32/obldc/usart_irq/usart_irq.c
+++ b/examples/stm32/obldc/usart_irq/usart_irq.c
@@ -80,7 +80,8 @@ void usart1_isr(void)
 	static u8 data = 'A';
 
 	/* Check if we were called because of RXNE. */
-	if ((USART_SR(USART1) & USART_SR_RXNE) != 0) {
+	if (((USART_CR1(USART1) & USART_SR_RXNEIE) != 0) &&
+		((USART_SR(USART1) & USART_SR_RXNE) != 0)) {
 		/* Indicate that we got data. */
 		gpio_toggle(GPIOA, GPIO6);
 
@@ -92,7 +93,8 @@ void usart1_isr(void)
 	}
 
 	/* Check if we were called because of TXE. */
-	if ((USART_SR(USART1) & USART_SR_TXE) != 0) {
+	if ((USART_CR1(USART1) & USART_SR_TXEIE) != 0) &&
+		((USART_SR(USART1) & USART_SR_TXE) != 0)) {
 		/* Indicate that we are sending out data. */
 		gpio_toggle(GPIOA, GPIO7);