diff --git a/openldap.spec b/openldap.spec
index 238973794f65c78326bcc97758c557e68d75fa67..bbc75280ccf9c4ef0e9b9d36678496ede8256549 100644
--- a/openldap.spec
+++ b/openldap.spec
@@ -2,7 +2,7 @@
 
 Name:           openldap
 Version:        2.6.3
-Release:        3
+Release:        4
 Summary:        LDAP support libraries
 License:        OLDAP-2.8
 URL:            https://www.openldap.org/
@@ -128,6 +128,9 @@ popd
 %build
 
 %set_build_flags
+%if "%toolchain" == "clang"
+	export CFLAGS="$CFLAGS -Wno-error=int-conversion"
+%endif
 export CFLAGS="${CFLAGS} ${LDFLAGS} -Wl,--as-needed -DLDAP_CONNECTIONLESS -DLDAP_USE_NON_BLOCKING_TLS"
 
 pushd openldap-%{version}
@@ -392,6 +395,9 @@ popd
 %doc ltb-project-openldap-ppolicy-check-password-1.1/README.check_pwd
 
 %changelog
+* Thu Jul 27 2023 yoo <sunyuechi@iscas.ac.cn> - 2.6.3-4
+- fix clang build error
+
 * Tur May 30 2023 liyunfei <liyunfei33@huawei.com> - 2.6.3-3
 - add clang compile support