diff --git a/mrblib/print.rb b/mrblib/print.rb
index 9183f6bb2..68c7837f3 100644
--- a/mrblib/print.rb
+++ b/mrblib/print.rb
@@ -74,6 +74,7 @@ module Kernel
 
     def printf(*args)
       __printstr__(sprintf(*args))
+      nil
     end
   end
 end