diff --git a/master/fsm_foe.c b/master/fsm_foe.c
index 76fdbc9a..4470c91c 100644
--- a/master/fsm_foe.c
+++ b/master/fsm_foe.c
@@ -374,7 +374,7 @@ void ec_fsm_foe_state_ack_check(
 
     if (!ec_slave_mbox_check(fsm->datagram)) {
         // slave did not put anything in the mailbox yet
-        if (time_after(datagram->jiffies_received,
+        if (time_after(fsm->datagram->jiffies_received,
                     fsm->jiffies_start + EC_FSM_FOE_TIMEOUT_JIFFIES)) {
             ec_foe_set_tx_error(fsm, FOE_TIMEOUT_ERROR);
             EC_SLAVE_ERR(slave, "Timeout while waiting for ack response.\n");
@@ -736,7 +736,7 @@ void ec_fsm_foe_state_data_check(
     }
 
     if (!ec_slave_mbox_check(fsm->datagram)) {
-        if (time_after(datagram->jiffies_received,
+        if (time_after(fsm->datagram->jiffies_received,
                     fsm->jiffies_start + EC_FSM_FOE_TIMEOUT_JIFFIES)) {
             ec_foe_set_tx_error(fsm, FOE_TIMEOUT_ERROR);
             EC_SLAVE_ERR(slave, "Timeout while waiting for ack response.\n");