diff --git a/doc/NEWS.Rd b/doc/NEWS.Rd
index 01666c9689..babab53615 100644
--- a/doc/NEWS.Rd
+++ b/doc/NEWS.Rd
@@ -425,6 +425,10 @@
       or package manuals using \command{R CMD Rd2pdf}, it is ensured
       that this \R's \file{Rd.sty} takes precedence over any other
       (incompatible) versions in default \dQuote{texmf trees}.
+
+      \item \code{tools::Rd2latex()} no longer outputs an
+      \samp{\\inputencoding{utf8}} line by default;
+      such a declaration is obsolete since \LaTeX 2018-04-01.
     }
   }
 
diff --git a/src/library/tools/R/Rd2latex.R b/src/library/tools/R/Rd2latex.R
index 97607c512b..fcdbd8bdb2 100644
--- a/src/library/tools/R/Rd2latex.R
+++ b/src/library/tools/R/Rd2latex.R
@@ -61,7 +61,7 @@ latex_canonical_encoding  <- function(encoding)
 Rd2latex <- function(Rd, out = "", defines = .Platform$OS.type,
                      stages = "render",
 		     outputEncoding = "UTF-8", fragment = FALSE, ...,
-                     writeEncoding = TRUE,
+                     writeEncoding = outputEncoding != "UTF-8",
 		     concordance = FALSE)
 {
     encode_warn <- FALSE
diff --git a/src/library/tools/man/Rd2HTML.Rd b/src/library/tools/man/Rd2HTML.Rd
index 215175ee81..29a087e273 100644
--- a/src/library/tools/man/Rd2HTML.Rd
+++ b/src/library/tools/man/Rd2HTML.Rd
@@ -1,6 +1,6 @@
 % File src/library/tools/man/Rd2HTML.Rd
 % Part of the R package, https://www.R-project.org
-% Copyright 2008-2022 R Core Team
+% Copyright 2008-2025 R Core Team
 % Distributed under GPL 2 or later
 
 \name{Rd2HTML}
@@ -34,7 +34,7 @@ Rd2txt(Rd, out = "", package = "", defines = .Platform$OS.type,
 
 Rd2latex(Rd, out = "", defines = .Platform$OS.type,
          stages = "render", outputEncoding = "UTF-8",
-         fragment = FALSE, ..., writeEncoding = TRUE,
+         fragment = FALSE, ..., writeEncoding = outputEncoding != "UTF-8",
          concordance = FALSE)
 
 Rd2ex(Rd, out = "", defines = .Platform$OS.type,
@@ -75,7 +75,7 @@ Rd2ex(Rd, out = "", defines = .Platform$OS.type,
     standalone HTML file. If \code{FALSE}, the header and footer are
     omitted, so that the output can be combined with other fragments.
   }
-  \item{hooks}{A list of functions controlling details of
+  \item{hooks}{a list of functions controlling details of
     output. Currently the only component used is \code{pkg_href}, which
     is used by \code{pkg2HTML} to determine the output HTML file path
     given a package name as input. }
@@ -86,15 +86,16 @@ Rd2ex(Rd, out = "", defines = .Platform$OS.type,
       examples section is wrapped inside a \code{rcode} block. }
   \item{Links, Links2}{\code{NULL} or a named (by topics) character vector of
     links, as returned by \code{\link{findHTMLlinks}}.}
-  \item{options}{An optional named list of options to pass to
+  \item{options}{an optional named list of options to pass to
     \code{\link{Rd2txt_options}}.}
   \item{...}{ additional parameters to pass to \code{\link{parse_Rd}} when
     \code{Rd} is a filename. }
-  \item{writeEncoding}{should \verb{\inputencoding} lines be written in
-      the file for non-ASCII encodings?}
-  \item{commentDontrun}{should \verb{\dontrun} sections be commented
+  \item{writeEncoding}{logical: should an \verb{\inputencoding} line be written
+      for non-ASCII encodings? \LaTeX release 2018-04-01 and later
+      default to UTF-8; the declaration is obsolete in that case.}
+  \item{commentDontrun}{logical: should \verb{\dontrun} sections be commented
       out?}
-  \item{commentDonttest}{should \verb{\donttest} sections be commented out?}
+  \item{commentDonttest}{logical: should \verb{\donttest} sections be commented out?}
 }
 \details{
   These functions convert help documents: \code{Rd2HTML} produces HTML,
diff --git a/tests/testit.tex.save b/tests/testit.tex.save
index 88c3e74d84..e57d90b441 100644
--- a/tests/testit.tex.save
+++ b/tests/testit.tex.save
@@ -1,4 +1,3 @@
-\inputencoding{utf8}
 \HeaderA{testit}{An Rd Regression Test}{testit}
 \aliasB{\{}{testit}{.Rlbrace.}
 %
diff --git a/tests/ver20.tex.save b/tests/ver20.tex.save
index 96e1327fe2..84fbeefe90 100644
--- a/tests/ver20.tex.save
+++ b/tests/ver20.tex.save
@@ -1,4 +1,3 @@
-\inputencoding{utf8}
 \HeaderA{ver20}{Johnson \& Johnson,  \$ \_  \#\#\# \textasciicircum{} \textasciitilde{}}{ver20}
 %
 \begin{Description}