diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index cba2385..4819c3d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -797,8 +797,9 @@
 				p = pack_hex_byte(p, hi);
 			else
 				*p++ = hex_asc_lo(hi);
+			p = pack_hex_byte(p, lo);
 		}
-		if (hi || lo > 0x0f)
+		else if (lo > 0x0f)
 			p = pack_hex_byte(p, lo);
 		else
 			*p++ = hex_asc_lo(lo);