1 files changed, 4 insertions, 1 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 39c99fea7c03..41da0741a663 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1485,7 +1485,10 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
                                 num = va_arg(args, long);
                                 break;
                         case FORMAT_TYPE_SIZE_T:
-                                num = va_arg(args, size_t);
+                                if (spec.flags & SIGN)
+                                        num = va_arg(args, ssize_t);
+                                else
+                                        num = va_arg(args, size_t);
                                 break;
                         case FORMAT_TYPE_PTRDIFF:
                                 num = va_arg(args, ptrdiff_t);