diff --git a/src/basic/ether-addr-util.h b/src/basic/ether-addr-util.h
index 63447910c0..794fc55bb8 100644
--- a/src/basic/ether-addr-util.h
+++ b/src/basic/ether-addr-util.h
@@ -23,7 +23,9 @@ struct hw_addr_data {
 #define HW_ADDR_TO_STRING_MAX (3*HW_ADDR_MAX_SIZE)
 char* hw_addr_to_string(const struct hw_addr_data *addr, char buffer[HW_ADDR_TO_STRING_MAX]);
 
-/* Use only as function argument, never stand-alone! */
+/* Note: the lifetime of the compound literal is the immediately surrounding block,
+ * see C11 §6.5.2.5, and
+ * https://stackoverflow.com/questions/34880638/compound-literal-lifetime-and-if-blocks */
 #define HW_ADDR_TO_STR(hw_addr) hw_addr_to_string((hw_addr), (char[HW_ADDR_TO_STRING_MAX]){})
 
 #define HW_ADDR_NULL ((const struct hw_addr_data){})
diff --git a/src/test/meson.build b/src/test/meson.build
index e106059182..14725248ce 100644
--- a/src/test/meson.build
+++ b/src/test/meson.build
@@ -44,6 +44,8 @@ test_dlopen_c = files('test-dlopen.c')
 tests += [
         [['src/test/test-device-nodes.c']],
 
+        [['src/test/test-ether-addr-util.c']],
+
         [['src/test/test-engine.c'],
          [libcore,
           libshared],
diff --git a/src/test/test-ether-addr-util.c b/src/test/test-ether-addr-util.c
new file mode 100644
index 0000000000..894215844a
--- /dev/null
+++ b/src/test/test-ether-addr-util.c
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "ether-addr-util.h"
+#include "tests.h"
+
+#define INFINIBAD_ADDR_1 ((const struct hw_addr_data){ .length = 20, .infiniband = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20} })
+
+static void test_HW_ADDR_TO_STRING(void) {
+        log_info("/* %s */", __func__);
+
+        const char *s = HW_ADDR_TO_STR(&(const struct hw_addr_data){6});
+        log_info("null: %s", s);
+
+        log_info("null×2: %s, %s",
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){6}),
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){6}));
+        log_info("null×3: %s, %s, %s",
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){6}),
+                 s,
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){6}));
+
+        log_info("infiniband: %s", HW_ADDR_TO_STR(&INFINIBAD_ADDR_1));
+
+        /* Let's nest function calls in a stupid way. */
+        _cleanup_free_ char *t = NULL;
+        log_info("infiniband×3: %s\n%14s%s\n%14s%s",
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){20}), "",
+                 t = strdup(HW_ADDR_TO_STR(&INFINIBAD_ADDR_1)), "",
+                 HW_ADDR_TO_STR(&(const struct hw_addr_data){20}));
+
+        const char *p;
+        /* Let's use a separate selection statement */
+        if ((p = HW_ADDR_TO_STR(&(const struct hw_addr_data){6})))
+                log_info("joint: %s, %s", s, p);
+}
+
+int main(int argc, char *argv[]) {
+        test_setup_logging(LOG_INFO);
+
+        test_HW_ADDR_TO_STRING();
+        return 0;
+}