--- a/src/hotspot/share/classfile/dictionary.cpp	Fri Mar 02 10:42:32 2018 -0800
+++ b/src/hotspot/share/classfile/dictionary.cpp	Fri Mar 02 17:25:55 2018 -0500
@@ -481,6 +481,7 @@
 void Dictionary::reorder_dictionary_for_sharing() {
 
   // Copy all the dictionary entries into a single master list.
+  assert(DumpSharedSpaces, "Should only be used at dump time");
 
   DictionaryEntry* master_list = NULL;
   for (int i = 0; i < table_size(); ++i) {
@@ -488,7 +489,7 @@
     while (p != NULL) {
       DictionaryEntry* next = p->next();
       InstanceKlass*ik = p->instance_klass();
-      if (ik->signers() != NULL) {
+      if (ik->has_signer_and_not_archived()) {
         // We cannot include signed classes in the archive because the certificates
         // used during dump time may be different than those used during
         // runtime (due to expiration, etc).