diff --git a/backport-posixtm-pacify-clang-18.patch b/backport-posixtm-pacify-clang-18.patch
new file mode 100644
index 0000000000000000000000000000000000000000..e337b7cbb63c069fccae28ef32ab3e11dfa4a3a5
--- /dev/null
+++ b/backport-posixtm-pacify-clang-18.patch
@@ -0,0 +1,33 @@
+From 67c298c36f69b6906840b7584be06b7b5f33f829 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Tue, 16 Jan 2024 17:21:08 -0800
+Subject: [PATCH] posixtm: pacify clang 18
+
+Problem reported by Khem Raj in:
+https://lists.gnu.org/r/bug-gnulib/2024-01/msg00045.html
+* lib/posixtm.c (posixtime): Pacify clang 18 by converting bool to int.
+Arguably this is a bug in draft C2x, since the non-pointer args to
+ckd_add should promote just like any other expressions do;
+but that’s not clang’s fault.
+
+Reference: https://github.com/coreutils/gnulib/commit/67c298c36f69b6906840b7584be06b7b5f33f829
+---
+ lib/posixtm.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/posixtm.c b/lib/posixtm.c
+index 43d65f5..1c4e344 100644
+--- a/lib/posixtm.c
++++ b/lib/posixtm.c
+@@ -191,7 +191,7 @@ posixtime (time_t *p, const char *s, unsigned int syntax_bits)
+              | (tm0.tm_min ^ tm1.tm_min)
+              | (tm0.tm_sec ^ tm1.tm_sec)))
+         {
+-          if (ckd_add (&t, t, leapsec))
++          if (ckd_add (&t, t, +leapsec))
+             return false;
+           *p = t;
+           return true;
+-- 
+2.50.1
+
diff --git a/coreutils.spec b/coreutils.spec
index 38b6cc1742c41b144f529ca77b54ee4327a6a7ba..7dea1b1241a62582ea7a93307b9a5a155c7d3d67 100644
--- a/coreutils.spec
+++ b/coreutils.spec
@@ -1,6 +1,6 @@
 Name:       coreutils
 Version:    9.4
-Release:    17
+Release:    18
 License:    GPLv3+
 Summary:    A set of basic GNU tools commonly used in shell scripts
 Url:        https://www.gnu.org/software/coreutils/
@@ -45,6 +45,7 @@ Patch30:   backport-yes-avoid-failure-on-CHERI-protected-systems.patch
 Patch31:   backport-cat-fix-plain-cat-bug.patch
 Patch32:   backport-tail-avoid-infloop-with-c-on-dev-zero.patch
 Patch33:   backport-CVE-2025-5278.patch
+Patch34:   backport-posixtm-pacify-clang-18.patch
 
 Patch9001:   coreutils-9.0-sw.patch
 
@@ -189,6 +190,9 @@ fi
 %{_mandir}/man*/*
 
 %changelog
+* Mon Jul 14 2025 jchzhou <zhoujiacheng@iscas.ac.cn> - 9.4-18
+- backport a patch to address clang building issues
+
 * Sat May 31 2025 Funda Wang <fundawang@yeah.net> - 9.4-17
 - fix CVE-2025-5278