diff --git a/[refs] b/[refs]
index 1a78c7fe27cc..17a320ab97ad 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2fa72c8fa5d03c4e07894ccb9f0be72e8687a455
+refs/heads/master: ef12496022d5917cfe0b04cf8fd685fc6bc08400
diff --git a/trunk/lib/vsprintf.c b/trunk/lib/vsprintf.c
index 39c99fea7c03..41da0741a663 100644
--- a/trunk/lib/vsprintf.c
+++ b/trunk/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);