diff --git a/os/hal/lib/streams/chprintf.c b/os/hal/lib/streams/chprintf.c
index 33134da96..4ecec7bcf 100644
--- a/os/hal/lib/streams/chprintf.c
+++ b/os/hal/lib/streams/chprintf.c
@@ -315,7 +315,7 @@ unsigned_common:
       width = -width;
     }
     if (width < 0) {
-      if (*s == '-' && filler == '0') {
+      if ((*s == '-' || *s == '+') && filler == '0') {
         streamPut(chp, (uint8_t)*s++);
         n++;
         i--;
diff --git a/readme.txt b/readme.txt
index f06ffc3d9..f93df008d 100644
--- a/readme.txt
+++ b/readme.txt
@@ -74,6 +74,7 @@
 *****************************************************************************
 
 *** 20.3.3 ***
+- FIX: Fixed chsnprintf() sign mode/filler mode conflict (bug #1140)
 - NEW: RT, NIL: Renamed _THREADS_QUEUE_DECL to THREADS_QUEUE_DECL for
        consistency.
 - FIX: Fixed GCC 10 causes warning in factory module (bug #1139).