diff --git a/ports/stm32f10x/rs485.c b/ports/stm32f10x/rs485.c
index 91d8148f..99064921 100644
--- a/ports/stm32f10x/rs485.c
+++ b/ports/stm32f10x/rs485.c
@@ -110,17 +110,9 @@ bool rs485_receive_error(void)
     return false;
 }
 
-/*********************************************************************/ /**
-                                                                         * @brief
-                                                                         *USARTx
-                                                                         *interrupt
-                                                                         *handler
-                                                                         *sub-routine
-                                                                         * @param[in]
-                                                                         *None
-                                                                         * @return
-                                                                         *None
-                                                                         **********************************************************************/
+/**
+ * @brief USARTx interrupt handler sub-routine
+ */
 void USART2_IRQHandler(void)
 {
     uint8_t data_byte;
@@ -130,6 +122,12 @@ void USART2_IRQHandler(void)
         data_byte = USART_ReceiveData(USART2);
         (void)FIFO_Put(&Receive_Buffer, data_byte);
     }
+    if (USART_GetFlagStatus(USART2, USART_FLAG_ORE) != RESET) {
+        /* note: enabling RXNE interrupt also enables the ORE interrupt! */
+        /* dummy read to clear error state */
+        data_byte = USART_ReceiveData(USART2);
+        USART_ClearFlag(USART2, USART_FLAG_ORE);
+    }
 }
 
 /*************************************************************************
diff --git a/ports/stm32f4xx/rs485.c b/ports/stm32f4xx/rs485.c
index 41aa36b5..6c8fe62d 100644
--- a/ports/stm32f4xx/rs485.c
+++ b/ports/stm32f4xx/rs485.c
@@ -149,6 +149,9 @@ void USART6_IRQHandler(void)
     }
     /* check for errors and clear them */
     if (USART_GetFlagStatus(USART6, USART_FLAG_ORE) == SET) {
+        /* note: enabling RXNE interrupt also enables the ORE interrupt! */
+        /* dummy read to clear error state */
+        data_byte = USART_ReceiveData(USART6);
         USART_ClearFlag(USART6, USART_FLAG_ORE);
     }
     if (USART_GetFlagStatus(USART6, USART_FLAG_NE) == SET) {