diff --git a/libtdb-waf18-c99.patch b/libtdb-waf18-c99.patch
new file mode 100644
index 0000000..84dcf7a
--- /dev/null
+++ b/libtdb-waf18-c99.patch
@@ -0,0 +1,23 @@
+Avoid calling lib_func without a prototype.
+
+This commit mirrors the change in commit f4c0a750d4adebcf2342a44e85f04526c34
+("WAF: Fix detection of linker features")
+to buildtools/wafsamba/samba_conftests.py.  It fixes the check for rpath
+support with compilers in strict C99 mode.
+
+Submitted upstream: <https://gitlab.com/samba-team/samba/-/merge_requests/2807>
+
+diff --git a/buildtools/wafsamba/samba_waf18.py b/buildtools/wafsamba/samba_waf18.py
+index e2a078bd3a05fd78..cfdceea14ca4b706 100644
+--- a/buildtools/wafsamba/samba_waf18.py
++++ b/buildtools/wafsamba/samba_waf18.py
+@@ -209,7 +209,8 @@ def CHECK_LIBRARY_SUPPORT(conf, rpath=False, version_script=False, msg=None):
+         lib_node.parent.mkdir()
+         lib_node.write('int lib_func(void) { return 42; }\n', 'w')
+         main_node = bld.srcnode.make_node('main.c')
+-        main_node.write('int main(void) {return !(lib_func() == 42);}', 'w')
++        main_node.write('int lib_func(void);\n'
++                        'int main(void) {return !(lib_func() == 42);}', 'w')
+         linkflags = []
+         if version_script:
+             script = bld.srcnode.make_node('ldscript')
diff --git a/libtdb.spec b/libtdb.spec
index 38fb87a..5a538c3 100644
--- a/libtdb.spec
+++ b/libtdb.spec
@@ -4,7 +4,7 @@
 
 Name: libtdb
 Version: 1.4.7
-Release: 3%{?dist}
+Release: 4%{?dist}
 Summary: The tdb library
 License: LGPLv3+
 URL: http://tdb.samba.org/
@@ -16,6 +16,7 @@ Source2: tdb.keyring
 # Patches
 Patch0001: 0003-wafsamba-Fix-few-SyntaxWarnings-caused-by-regular-ex.patch
 Patch0002: libtdb-revert-breaking-tdb.h.patch
+Patch0003: libtdb-waf18-c99.patch
 
 BuildRequires: make
 BuildRequires: gcc
@@ -102,6 +103,9 @@ make install DESTDIR=$RPM_BUILD_ROOT
 %ldconfig_scriptlets
 
 %changelog
+* Wed Dec 14 2022 Florian Weimer <fweimer@redhat.com> - 1.4.7-4
+- C99 compatibility fix
+
 * Thu Jul 21 2022 Fedora Release Engineering <releng@fedoraproject.org> - 1.4.7-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild