diff --git a/runtime/doc/userfunc.txt b/runtime/doc/userfunc.txt
index 138f27e..1fe7800 100644
--- a/runtime/doc/userfunc.txt
+++ b/runtime/doc/userfunc.txt
@@ -443,7 +443,8 @@
 be followed by anything, such as "->func" or ".member".  Currently `:defer
 GetArg()->TheFunc()` does not work, it may work in a later version.
 
-Errors are reported but do not cause aborting execution of deferred functions.
+Errors are reported but do not cause aborting execution of deferred functions
+or altering execution outside of deferred functions.
 
 No range is accepted.  The function can be a partial with extra arguments, but
 not with a dictionary. *E1300*
diff --git a/runtime/doc/vim9class.txt b/runtime/doc/vim9class.txt
index 00bdf36..27184c8 100644
--- a/runtime/doc/vim9class.txt
+++ b/runtime/doc/vim9class.txt
@@ -28,7 +28,8 @@
 The fancy term is "object-oriented programming".  You can find lots of study
 material on this subject.  Here we document what |Vim9| script provides,
 assuming you know the basics already.  Added are helpful hints about how to
-use this functionality effectively.
+use this functionality effectively.  Vim9 classes and objects cannot be used
+in legacy Vim scripts and legacy functions.
 
 The basic item is an object:
 - An object stores state.  It contains one or more variables that can each