diff --git a/ChangeLog b/ChangeLog
index 712944ea..e7b0bc4e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2021-02-05  Simon Josefsson  <simon@josefsson.org>
+
+	Fix some autoreconf 2.71 warnings.
+
+	* configure.ac: Remove obsolete AC_HEADER_STDC, AC_HEADER_TIME,
+	AC_FUNC_SETVBUF_REVERSED, and AC_DECL_SYS_SIGLIST.  Don't check
+	for sys/time.h, we never use the test result.
+
 2021-02-01  Alfred M. Szmidt  <ams@gnu.org>
 
 	* ftp/ftp.c (getreply): Fix possible buffer overflow (backport
diff --git a/configure.ac b/configure.ac
index 86136fb3..43ce6160 100644
--- a/configure.ac
+++ b/configure.ac
@@ -613,8 +613,6 @@ IU_CHECK_LIBIDN([$with_libidn_prefix], [$with_idn])
 
 ### Checks for header files.
 
-AC_HEADER_STDC
-AC_HEADER_TIME
 AC_HEADER_DIRENT
 
 AC_CHECK_HEADERS([arpa/nameser.h arpa/tftp.h errno.h fcntl.h features.h \
@@ -625,7 +623,7 @@ AC_CHECK_HEADERS([arpa/nameser.h arpa/tftp.h errno.h fcntl.h features.h \
 		  sys/utsname.h sys/ptyvar.h sys/msgbuf.h sys/filio.h \
 		  sys/ioctl_compat.h sys/cdefs.h sys/stream.h sys/mkdev.h \
 		  sys/sockio.h sys/sysmacros.h sys/param.h sys/file.h \
-		  sys/proc.h sys/select.h sys/time.h sys/wait.h \
+		  sys/proc.h sys/select.h sys/wait.h \
                   sys/resource.h \
 		  stropts.h tcpd.h utmp.h utmpx.h unistd.h \
                   vis.h], [], [], [
@@ -769,7 +767,6 @@ IU_CHECK_WEAK_REFS
 
 ### Checks for library functions.
 AC_FUNC_CLOSEDIR_VOID
-AC_FUNC_SETVBUF_REVERSED
 AC_FUNC_FORK
 AC_FUNC_STRCOLL
 AC_FUNC_MMAP
@@ -902,8 +899,6 @@ AC_MSG_RESULT([$ac_iu_const_enctype_names])
 
 ## Checks for function declarations.
 
-AC_DECL_SYS_SIGLIST
-
 AC_CHECK_DECLS(crypt, , , [#include <unistd.h>])
 
 # EWOULDBLOCK is more or less the BSD version of posix EAGAIN.