diff --git a/test/meson.build b/test/meson.build
index b2b9929..607c873 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -57,6 +57,7 @@
     'message/unpack.cpp',
     include_directories: root_inc,
     build_by_default: false,
+    override_options: ['b_lundef=true'],
     implicit_include_directories: false,
     dependencies: [boost, phosphor_logging_dep, crypto, systemd, sdbusplus_dep, gtest, gmock]
   ))
diff --git a/test/message/payload.cpp b/test/message/payload.cpp
index 0114e11..38977e4 100644
--- a/test/message/payload.cpp
+++ b/test/message/payload.cpp
@@ -317,16 +317,9 @@
 
 extern "C"
 {
-int sd_journal_send(const char* format, ...)
+int sd_journal_sendv(const struct iovec* iov, int /* n */)
 {
-    logs.push_back(format);
-    return 0;
-}
-
-int sd_journal_send_with_location(const char* /*file*/, const char* /*line*/,
-                                  const char* /*func*/, const char* format, ...)
-{
-    logs.push_back(format);
+    logs.push_back(std::string((char*)iov[0].iov_base, iov[0].iov_len));
     return 0;
 }
 }