1 files changed, 1 insertions, 1 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 797428afd111..bed7229378f2 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -489,7 +489,7 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
                 if (str < end)
                         *str = '\0';
                 else
-                        *end = '\0';
+                        end[-1] = '\0';
         }
         /* the trailing null byte doesn't count towards the total */
         return str-buf;