diff --git a/runtime/doc/testing.txt b/runtime/doc/testing.txt
index f48984c..e728e27 100644
--- a/runtime/doc/testing.txt
+++ b/runtime/doc/testing.txt
@@ -123,6 +123,13 @@
 		Return a |String| that is null. Only useful for testing.
 
 
+test_unknown()						*test_unknown()*
+		Return a value with unknown type. Only useful for testing.
+
+test_void()						*test_void()*
+		Return a value with void type. Only useful for testing.
+
+
 test_option_not_set({name})				*test_option_not_set()*
 		Reset the flag that indicates option {name} was set.  Thus it
 		looks like it still has the default value. Use like this: >