diff --git a/lib/rubygems/specification.rb b/lib/rubygems/specification.rb
index 4124b831e7ac..71285326adeb 100644
--- a/lib/rubygems/specification.rb
+++ b/lib/rubygems/specification.rb
@@ -2819,7 +2819,7 @@ def validate packaging = true
 
     # Warnings
 
-    %w[author homepage summary].each do |attribute|
+    %w[author homepage summary files].each do |attribute|
       value = self.send attribute
       warning "no #{attribute} specified" if value.nil? or value.empty?
     end