diff --git a/include/can.h b/include/can.h
index 8376aea..e04676b 100644
--- a/include/can.h
+++ b/include/can.h
@@ -34,6 +34,7 @@ THE SOFTWARE.
 
 typedef struct {
 	CAN_TypeDef *instance;
+	uint32_t reg_esr_old;
 	uint16_t brp;
 	uint8_t phase_seg1;
 	uint8_t phase_seg2;
@@ -58,6 +59,7 @@ uint32_t can_get_error_status(can_data_t *hcan);
 
 /** parse status value returned by can_get_error_status().
  * @param frame : will hold the generated error frame
+ * @param err : holds the contents of the ESR register
  * @return 1 when status changes (if any) need a new error frame sent
  */
-bool can_parse_error_status(uint32_t err, uint32_t last_err, can_data_t *hcan, struct gs_host_frame *frame);
+bool can_parse_error_status(can_data_t *hcan, struct gs_host_frame *frame, uint32_t err);
diff --git a/src/can.c b/src/can.c
index b55c07c..27c4967 100644
--- a/src/can.c
+++ b/src/can.c
@@ -260,13 +260,15 @@ static bool status_is_active(uint32_t err)
 	return !(err & (CAN_ESR_BOFF | CAN_ESR_EPVF));
 }
 
-bool can_parse_error_status(uint32_t err, uint32_t last_err, can_data_t *hcan, struct gs_host_frame *frame)
+bool can_parse_error_status(can_data_t *hcan, struct gs_host_frame *frame, uint32_t err)
 {
+	uint32_t last_err = hcan->reg_esr_old;
 	/* We build up the detailed error information at the same time as we decide
 	 * whether there's anything worth sending. This variable tracks that final
 	 * result. */
 	bool should_send = false;
-	(void) hcan;
+
+	hcan->reg_esr_old = err;
 
 	frame->echo_id = 0xFFFFFFFF;
 	frame->can_id  = CAN_ERR_FLAG;
diff --git a/src/main.c b/src/main.c
index 26a10cb..b11fc9f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -55,7 +55,6 @@ static led_data_t hLED = {0};
 int main(void)
 {
 	can_data_t *channel = &hGS_CAN.channels[0];
-	uint32_t last_can_error_status = 0;
 
 	HAL_Init();
 	SystemClock_Config();
@@ -174,10 +173,8 @@ int main(void)
 				restore_irq(was_irq_enabled);
 
 				frame->timestamp_us = timer_get();
-				if (can_parse_error_status(can_err, last_can_error_status, channel, frame)) {
+				if (can_parse_error_status(channel, frame, can_err)) {
 					list_add_tail_locked(&frame_object->list, &hGS_CAN.list_to_host);
-
-					last_can_error_status = can_err;
 				} else {
 					list_add_tail_locked(&frame_object->list, &hGS_CAN.list_frame_pool);
 				}