--- a/src/hotspot/share/oops/cpCache.cpp	Thu Jan 18 09:01:00 2018 -0800
+++ b/src/hotspot/share/oops/cpCache.cpp	Thu Jan 18 18:58:46 2018 +0000
@@ -177,6 +177,7 @@
       // instruction somehow links to a non-interface method (in Object).
       // In that case, the method has no itable index and must be invoked as a virtual.
       // Set a flag to keep track of this corner case.
+      assert(method->is_public(), "Calling non-public method in Object with invokeinterface");
       change_to_virtual = true;
 
       // ...and fall through as if we were handling invokevirtual: