diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index d6cce6d..3127c9d 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -310,6 +310,8 @@
 
     if (lo < 0)
         lo = 0;
+    if (hi < lo)
+        hi = lo;
     if (hi > self->ob_size)
         hi = self->ob_size;