diff --git a/src/libsystemd/libsystemd.sym b/src/libsystemd/libsystemd.sym
index a6748ceb20..a9ab0605ce 100644
--- a/src/libsystemd/libsystemd.sym
+++ b/src/libsystemd/libsystemd.sym
@@ -676,3 +676,8 @@ LIBSYSTEMD_241 {
 global:
         sd_bus_close_unref;
 } LIBSYSTEMD_240;
+
+LIBSYSTEMD_243 {
+global:
+        sd_bus_object_vtable_format;
+} LIBSYSTEMD_241;
diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c
index d9fc25605a..ce2cb94bde 100644
--- a/src/libsystemd/sd-bus/bus-objects.c
+++ b/src/libsystemd/sd-bus/bus-objects.c
@@ -1701,7 +1701,8 @@ struct sd_bus_vtable_original {
 #define VTABLE_ELEMENT_SIZE sizeof(struct sd_bus_vtable)
 
 static int vtable_features(const sd_bus_vtable *vtable) {
-        if (vtable[0].x.start.element_size == VTABLE_ELEMENT_SIZE_ORIGINAL)
+        if (vtable[0].x.start.element_size < VTABLE_ELEMENT_SIZE ||
+            !vtable[0].x.start.vtable_format_reference)
                 return 0;
         return vtable[0].x.start.features;
 }
@@ -1928,6 +1929,9 @@ fail:
         return r;
 }
 
+/* This symbol exists solely to tell the linker that the "new" vtable format is used. */
+_public_ const unsigned sd_bus_object_vtable_format = 242;
+
 _public_ int sd_bus_add_object_vtable(
                 sd_bus *bus,
                 sd_bus_slot **slot,
diff --git a/src/systemd/sd-bus-vtable.h b/src/systemd/sd-bus-vtable.h
index 8a73ef0503..e3804e203c 100644
--- a/src/systemd/sd-bus-vtable.h
+++ b/src/systemd/sd-bus-vtable.h
@@ -52,6 +52,15 @@ enum {
         _SD_BUS_VTABLE_PARAM_NAMES     = 1 << 0,
 };
 
+extern const unsigned sd_bus_object_vtable_format;
+
+/* Note: unused areas in the sd_bus_vtable[] array must be initalized to 0. The stucture contains an embedded
+ * union, and the compiler is NOT required to initalize the unused areas of the union when the rest of the
+ * structure is initalized. Normally the array is defined as read-only data, in which case the linker places
+ * it in the BSS section, which is always fully initalized, so this is not a concern. But if the array is
+ * created on the stack or on the heap, care must be taken to initalize the unused areas, for examply by
+ * first memsetting the whole region to zero before filling the data in. */
+
 struct sd_bus_vtable {
         /* Please do not initialize this structure directly, use the
          * macros below instead */
@@ -62,6 +71,7 @@ struct sd_bus_vtable {
                 struct {
                         size_t element_size;
                         uint64_t features;
+                        const unsigned *vtable_format_reference;
                 } start;
                 struct {
                         const char *member;
@@ -93,7 +103,8 @@ struct sd_bus_vtable {
                 .x = {                                                  \
                     .start = {                                          \
                         .element_size = sizeof(sd_bus_vtable),          \
-                        .features = _SD_BUS_VTABLE_PARAM_NAMES          \
+                        .features = _SD_BUS_VTABLE_PARAM_NAMES,         \
+                        .vtable_format_reference = &sd_bus_object_vtable_format, \
                     },                                                  \
                 },                                                      \
         }
diff --git a/src/test/generate-sym-test.py b/src/test/generate-sym-test.py
index 357cce8e44..2510809452 100755
--- a/src/test/generate-sym-test.py
+++ b/src/test/generate-sym-test.py
@@ -6,18 +6,22 @@ for header in sys.argv[2:]:
     print('#include "{}"'.format(header.split('/')[-1]))
 
 print('''
-void* functions[] = {''')
+const void* symbols[] = {''')
 
 for line in open(sys.argv[1]):
     match = re.search('^ +([a-zA-Z0-9_]+);', line)
     if match:
-        print('    {},'.format(match.group(1)))
+        s = match.group(1)
+        if s == 'sd_bus_object_vtable_format':
+            print(f'    &{s},')
+        else:
+            print(f'    {s},')
 
 print('''};
 
 int main(void) {
     unsigned i;
-    for (i = 0; i < sizeof(functions)/sizeof(void*); i++)
-         printf("%p\\n", functions[i]);
+    for (i = 0; i < sizeof(symbols)/sizeof(void*); i++)
+         printf("%p\\n", symbols[i]);
     return 0;
 }''')