--- old/src/hotspot/share/opto/memnode.cpp	2018-11-06 21:04:20.400792895 +0100
+++ new/src/hotspot/share/opto/memnode.cpp	2018-11-06 21:04:20.247794189 +0100
@@ -1734,7 +1734,7 @@
         && Opcode() != Op_LoadKlass && Opcode() != Op_LoadNKlass) {
       // t might actually be lower than _type, if _type is a unique
       // concrete subclass of abstract class t.
-      if (off_beyond_header) {  // is the offset beyond the header?
+      if (off_beyond_header || off == Type::OffsetBot) {  // is the offset beyond the header?
         const Type* jt = t->join_speculative(_type);
         // In any case, do not allow the join, per se, to empty out the type.
         if (jt->empty() && !t->empty()) {