diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index ac823aa..153cdf9 100644
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -2469,11 +2469,6 @@ _public_ int sd_bus_message_append(sd_bus_message *m, const char *types, ...) {
         va_list ap;
         int r;
 
-        assert_return(m, -EINVAL);
-        assert_return(types, -EINVAL);
-        assert_return(!m->sealed, -EPERM);
-        assert_return(!m->poisoned, -ESTALE);
-
         va_start(ap, types);
         r = sd_bus_message_appendv(m, types, ap);
         va_end(ap);
@@ -4524,10 +4519,6 @@ _public_ int sd_bus_message_read(sd_bus_message *m, const char *types, ...) {
         va_list ap;
         int r;
 
-        assert_return(m, -EINVAL);
-        assert_return(m->sealed, -EPERM);
-        assert_return(types, -EINVAL);
-
         va_start(ap, types);
         r = message_read_ap(m, types, ap);
         va_end(ap);