diff --git a/lib/thor/actions/inject_into_file.rb b/lib/thor/actions/inject_into_file.rb
index fd0046b5..2635e755 100644
--- a/lib/thor/actions/inject_into_file.rb
+++ b/lib/thor/actions/inject_into_file.rb
@@ -21,7 +21,7 @@ module Actions
     #     gems.split(" ").map{ |gem| "  config.gem :#{gem}" }.join("\n")
     #   end
     #
-    WARNINGS = { unchanged_no_flag: 'File unchanged! The supplied flag value not found!' }
+    WARNINGS = { unchanged_no_flag: 'File unchanged! Either the supplied flag value not found or the content has already been inserted!' }
 
     def insert_into_file(destination, *args, &block)
       data = block_given? ? block : args.shift