diff --git a/.gitignore b/.gitignore
index 7b60760..26bee69 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,7 +19,6 @@
 /libcharset/build-aux/libtool-reloc
 /libcharset/m4/codeset.m4
 /libcharset/m4/fcntl-o.m4
-/libcharset/m4/glibc21.m4
 /libcharset/m4/lib-ld.m4
 /libcharset/m4/relocatable-lib.m4
 /libcharset/m4/relocatable.m4
@@ -130,7 +129,6 @@
 /srcm4/getprogname.m4
 /srcm4/gettext.m4
 /srcm4/glibc2.m4
-/srcm4/glibc21.m4
 /srcm4/gnulib-common.m4
 /srcm4/gnulib-comp.m4
 /srcm4/gnulib-tool.m4
diff --git a/ChangeLog b/ChangeLog
index 088d17d..cfdf145 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2019-07-02  Bruno Haible  <bruno@clisp.org>
+
+	Drop unused macro gl_GLIBC21.
+	* autogen.sh: Don't copy glibc21.m4.
+
 2019-05-22  Bruno Haible  <bruno@clisp.org>
 
 	Fix comment.
diff --git a/autogen.sh b/autogen.sh
index f53e1bb..e9a8a50 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -72,7 +72,7 @@
 for file in config.guess config.libpath config.sub install-sh libtool-reloc mkinstalldirs; do
   cp -p build-aux/$file libcharset/build-aux/$file || exit $?
 done
-for file in codeset.m4 fcntl-o.m4 glibc21.m4 lib-ld.m4 relocatable.m4 relocatable-lib.m4 visibility.m4; do
+for file in codeset.m4 fcntl-o.m4 lib-ld.m4 relocatable.m4 relocatable-lib.m4 visibility.m4; do
   cp -p srcm4/$file libcharset/m4/$file || exit $?
 done
 
diff --git a/libcharset/ChangeLog b/libcharset/ChangeLog
index 3da0683..d5f6657 100644
--- a/libcharset/ChangeLog
+++ b/libcharset/ChangeLog
@@ -1,3 +1,10 @@
+2019-07-02  Bruno Haible  <bruno@clisp.org>
+
+	Drop unused macro gl_GLIBC21.
+	* configure.ac: Don't invoke gl_GLIBC21.
+	* Makefile.in (PARENT_IMPORTED_FILES): Remove m4/glibc21.m4.
+	* INTEGRATE: Update.
+
 2019-06-30  Bruno Haible  <bruno@clisp.org>
 
 	Fix build error with MSVC.
diff --git a/libcharset/INTEGRATE b/libcharset/INTEGRATE
index 454c557..a9b59ea 100644
--- a/libcharset/INTEGRATE
+++ b/libcharset/INTEGRATE
@@ -8,15 +8,14 @@
 * Copy the lib/ source file (localcharset.c) and the include file
   (include/localcharset.h) into your package.
 
-* Add the m4/ files (codeset.m4, fcntl_h.m4, glibc21.m4) to your aclocal.m4
-  file or, if you are using automake, to your m4/ directory.
+* Add the m4/ files (codeset.m4, fcntl_h.m4) to your aclocal.m4 file
+  or, if you are using automake, to your m4/ directory.
 
 * Add the following lines to your configure.ac file:
 
     AC_CANONICAL_HOST
     AM_LANGINFO_CODESET
     gl_FCNTL_O_FLAGS
-    jm_GLIBC21
     AC_CHECK_HEADERS([stddef.h stdlib.h string.h])
 
   and make sure that it sets and AC_SUBSTs the PACKAGE variable.
diff --git a/libcharset/Makefile.in b/libcharset/Makefile.in
index e048197..2f9874b 100644
--- a/libcharset/Makefile.in
+++ b/libcharset/Makefile.in
@@ -121,7 +121,6 @@
   build-aux/mkinstalldirs \
   m4/codeset.m4 \
   m4/fcntl-o.m4 \
-  m4/glibc21.m4 \
   m4/visibility.m4
 IMPORTED_FILES = \
   COPYING.LIB \
diff --git a/libcharset/configure.ac b/libcharset/configure.ac
index a071d25..593e990 100644
--- a/libcharset/configure.ac
+++ b/libcharset/configure.ac
@@ -55,7 +55,6 @@
 
 AM_LANGINFO_CODESET
 gl_FCNTL_O_FLAGS
-gl_GLIBC21
 AC_CHECK_FUNCS([setlocale])
 
 AC_CONFIG_FILES([Makefile])