diff --git a/os/various/chprintf.c b/os/various/chprintf.c
index 08d313dac..8c709bc4f 100644
--- a/os/various/chprintf.c
+++ b/os/various/chprintf.c
@@ -246,12 +246,12 @@ unsigned_common:
         chSequentialStreamPut(chp, (uint8_t)*s++);
         i--;
       }
-      do
+      do {
         chSequentialStreamPut(chp, (uint8_t)filler);
-      while (++width != 0);
+      } while (++width != 0);
     }
-    chSequentialStreamWrite(chp, (uint8_t*)s, i);
-    s += i;
+    while (--i >= 0)
+      chSequentialStreamPut(chp, (uint8_t)*s++);
 
     while (width) {
       chSequentialStreamPut(chp, (uint8_t)filler);
diff --git a/readme.txt b/readme.txt
index e486f007f..e7afb49cb 100644
--- a/readme.txt
+++ b/readme.txt
@@ -112,6 +112,8 @@
   (backported to 2.6.4).
 - FIX: Fixed wrong TIM1 and TIM8 macros in STM32F30x HAL driver (bug #473)
   (backported to 2.6.4).
+- FIX: Fixed chprintf()/chSequentialStreamWrite() crash with size of 0
+  or NULL (bug #472)(backported to 2.6.4).
 - FIX: Fixed STM32 SDC driver clock activation issue (bug #464)(backported to
 - FIX: Fixed simulated IO message is corrupted in simulator (bug #468)
   (backported to 2.6.4).