diff --git a/ChangeLog b/ChangeLog
index 3cfb8d854e..bee63a802f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2024-10-07  Bruno Haible  <bruno@clisp.org>
+
+	mntent: Fix syntax error when module 'hasmntopt' is not in use.
+	Reported by Bernhard Voelker <mail@bernhard-voelker.de> in
+	<https://lists.gnu.org/archive/html/bug-gnulib/2024-10/msg00039.html>.
+	* modules/mntent (configure.ac): Invoke gl_MNTENT_H_REQUIRE_DEFAULTS.
+
 2024-10-07  Bruno Haible  <bruno@clisp.org>
 
 	file-has-acl: Fix test failure on Cygwin.
diff --git a/modules/mntent b/modules/mntent
index 8dc48c38d0..e0926b4760 100644
--- a/modules/mntent
+++ b/modules/mntent
@@ -14,6 +14,7 @@ snippet/warn-on-use
 
 configure.ac:
 gl_MNTENT_H
+gl_MNTENT_H_REQUIRE_DEFAULTS
 gl_CONDITIONAL_HEADER([mntent.h])
 AC_PROG_MKDIR_P