diff --git a/lib/redis/namespace.rb b/lib/redis/namespace.rb
index fa3b34d..4f16841 100644
--- a/lib/redis/namespace.rb
+++ b/lib/redis/namespace.rb
@@ -366,6 +366,7 @@ def call_with_namespace(command, *args, &block)
       # Add the namespace to any parameters that are keys.
       case before
       when :first
+        args.flatten!
         args[0] = add_namespace(args[0]) if args[0]
       when :all
         args = add_namespace(args)