diff --git a/os/various/chprintf.c b/os/various/chprintf.c
index c97ea0cf2..d712b98ab 100644
--- a/os/various/chprintf.c
+++ b/os/various/chprintf.c
@@ -137,7 +137,7 @@ void chprintf(BaseSequentialStream *chp, const char *fmt, ...) {
       left_align = TRUE;
     }
     filler = ' ';
-    if (*fmt == '.') {
+    if ((*fmt == '.') || (*fmt == '0')) {
       fmt++;
       filler = '0';
     }
diff --git a/readme.txt b/readme.txt
index eba129fc2..953b51cec 100644
--- a/readme.txt
+++ b/readme.txt
@@ -92,6 +92,7 @@
 - FIX: Fixed lwipthread.h should explicitly include lwip/opts.h (bug #414).
 - FIX: Fixed STM32_PLLI2SCLKOUT miscalculated (bug #413)(backported to 2.4.4).
 - FIX: Fixed wrong RTC vector name in STM32F1/F4/L1 EXT drivers (bug #412).
+- FIX: Fixed fill character error in chprintf (bug #411).
 - FIX: Fixed wrong STM32 USBv1 driver behavior (bug #410).
 - FIX: Fixed STM32 wrong peripherals reset procedure (bug #409)(backported
   to 2.4.4).