--- a/src/hotspot/share/oops/cpCache.cpp	Fri Dec 15 16:51:13 2017 +0100
+++ b/src/hotspot/share/oops/cpCache.cpp	Fri Dec 15 11:23:50 2017 -0500
@@ -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: