diff --git a/readme.txt b/readme.txt
index a99d8c1f9..507be741f 100644
--- a/readme.txt
+++ b/readme.txt
@@ -82,6 +82,7 @@
 *****************************************************************************
 
 *** 2.5.1 ***
+- FIX: Fixed missing ; in testmbox.c (bug 3585979)(backported to 2.4.3).
 - FIX: Fixed STM32F4xx: Wrong CAN1 SCE interrupt number definition (bug
   3581571).
 - FIX: Fixed STM32_P407: implement mmc_lld_is_card_inserted (bug 3581929)
diff --git a/test/testmbox.c b/test/testmbox.c
index 9c0bc08fa..5d3b7f153 100644
--- a/test/testmbox.c
+++ b/test/testmbox.c
@@ -169,7 +169,7 @@ static void mbox1_execute(void) {
   msg1 = chMBPostI(&mb1, 'D');
   test_assert(25, msg1 == RDY_OK, "wrong wake-up message");
   msg1 = chMBPostI(&mb1, 'E');
-  chSysUnlock()
+  chSysUnlock();
   test_assert(26, msg1 == RDY_OK, "wrong wake-up message");
   test_assert(27, mb1.mb_rdptr == mb1.mb_wrptr, "pointers not aligned");
   for (i = 0; i < MB_SIZE; i++) {