diff --git a/os/hal/platforms/STM32/can_lld.c b/os/hal/platforms/STM32/can_lld.c
index 75de38353..6c12cc145 100644
--- a/os/hal/platforms/STM32/can_lld.c
+++ b/os/hal/platforms/STM32/can_lld.c
@@ -217,7 +217,7 @@ static void can_lld_sce_handler(CANDriver *canp) {
     chSysLockFromIsr();
     /* The content of the ESR register is copied unchanged in the upper
        half word of the listener flags mask.*/
-    chEvtBroadcastFlagsI(&canp->error_event, flags | (flagsmask_t)(esr < 16));
+    chEvtBroadcastFlagsI(&canp->error_event, flags | (flagsmask_t)(esr << 16));
     chSysUnlockFromIsr();
   }
 }
diff --git a/readme.txt b/readme.txt
index 83bd24c24..e38983590 100644
--- a/readme.txt
+++ b/readme.txt
@@ -85,6 +85,8 @@
 *****************************************************************************
 
 *** 2.5.2 ***
+- FIX: Fixed typo in platforms/STM32/can_lld.c (bug 3604657)(backported
+  to 2.4.4).
 - FIX: Added board files and demo for "WaveShare Open STM32F4 207I-C / 407I-C".
   Added ULPI support to the STM32 USB (OTG-HS) driver.
   Contributed by Dave Camarillo (bug 3603362).