diff --git a/src/library/base/man/difftime.Rd b/src/library/base/man/difftime.Rd
index d40920c32b..4fb0391f2c 100644
--- a/src/library/base/man/difftime.Rd
+++ b/src/library/base/man/difftime.Rd
@@ -27,6 +27,7 @@
 \alias{units.difftime}
 \alias{units<-.difftime}
 \alias{time interval} % used by mean.Rd
+\alias{summary.difftime}
 \description{
   Time intervals creation, printing, and some arithmetic.  The
   \code{\link{print}()} method calls these \dQuote{time differences}.
diff --git a/src/library/base/man/sets.Rd b/src/library/base/man/sets.Rd
index b3c0ce4cc0..d8479a80a5 100644
--- a/src/library/base/man/sets.Rd
+++ b/src/library/base/man/sets.Rd
@@ -43,7 +43,8 @@ is.element(el, set)
   to character vectors).  Starting with \R 4.5.0, operands of the
   \dQuote{same kind} (in the sense that \code{\link{isa}(x, class(y))}
   or \code{\link{isa}(y, class(x))} which appear to be
-  \dQuote{vector-like} (in the sense that subscripting \code{x} and/or
+  \dQuote{vector-like} (in the sense that \code{dim(x)} has length at
+  most one, and subscripting \code{x} and/or
   \code{y} by \code{0L} leaves the class unchanged) are no longer
   transformed.   In particular, union, intersection and set difference
   of two factors now give factors (see the examples).