diff --git a/lib/identity_cache/parent_model_expiration.rb b/lib/identity_cache/parent_model_expiration.rb
index a8e290ee..fcd9e0e0 100644
--- a/lib/identity_cache/parent_model_expiration.rb
+++ b/lib/identity_cache/parent_model_expiration.rb
@@ -41,17 +41,6 @@ def parent_expiration_entries
         ParentModelExpiration.install_pending_parent_expiry_hooks(cached_model)
         _parent_expiration_entries
       end
-
-      def check_for_unsupported_parent_expiration_entries
-        return unless parent_expiration_entries.any?
-        msg = +"Unsupported manual expiration of #{name} record that is embedded in parent associations:\n"
-        parent_expiration_entries.each do |association_name, cached_associations|
-          cached_associations.each do |parent_class, _only_on_foreign_key_change|
-            msg << "- #{association_name}"
-          end
-        end
-        raise msg
-      end
     end
 
     included do
diff --git a/lib/identity_cache/without_primary_index.rb b/lib/identity_cache/without_primary_index.rb
index 3c0af040..05702dc0 100644
--- a/lib/identity_cache/without_primary_index.rb
+++ b/lib/identity_cache/without_primary_index.rb
@@ -75,6 +75,19 @@ def expire_cache_for_update(old_indexed_values, changes)
       alias_method :expire_cache_for_insert, :expire_cache_for_insert_or_delete
 
       alias_method :expire_cache_for_delete, :expire_cache_for_insert_or_delete
+
+      private
+
+      def check_for_unsupported_parent_expiration_entries
+        return unless parent_expiration_entries.any?
+        msg = +"Unsupported manual expiration of #{name} record that is embedded in parent associations:\n"
+        parent_expiration_entries.each do |association_name, cached_associations|
+          cached_associations.each do |parent_class, _only_on_foreign_key_change|
+            msg << "- #{association_name}"
+          end
+        end
+        raise msg
+      end
     end
   end
 end