diff --git a/src/libsystemd/sd-bus/bus-convenience.c b/src/libsystemd/sd-bus/bus-convenience.c
index 4ec061644d..89547a252d 100644
--- a/src/libsystemd/sd-bus/bus-convenience.c
+++ b/src/libsystemd/sd-bus/bus-convenience.c
@@ -96,6 +96,7 @@ _public_ int sd_bus_call_method(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(!bus_pid_changed(bus), -ECHILD, error);
 
         if (!BUS_IS_OPEN(bus->state)) {
@@ -283,6 +284,7 @@ _public_ int sd_bus_get_property(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error);
         bus_assert_return(member_name_is_valid(member), -EINVAL, error);
         bus_assert_return(reply, -EINVAL, error);
@@ -294,7 +296,10 @@ _public_ int sd_bus_get_property(
                 goto fail;
         }
 
-        r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &rep, "ss", strempty(interface), member);
+        r = sd_bus_call_method(bus, destination, path,
+                               "org.freedesktop.DBus.Properties", "Get",
+                               error, &rep,
+                               "ss", strempty(interface), member);
         if (r < 0)
                 return r;
 
@@ -324,6 +329,7 @@ _public_ int sd_bus_get_property_trivial(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error);
         bus_assert_return(member_name_is_valid(member), -EINVAL, error);
         bus_assert_return(bus_type_is_trivial(type), -EINVAL, error);
@@ -368,6 +374,7 @@ _public_ int sd_bus_get_property_string(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error);
         bus_assert_return(member_name_is_valid(member), -EINVAL, error);
         bus_assert_return(ret, -EINVAL, error);
@@ -416,6 +423,7 @@ _public_ int sd_bus_get_property_strv(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error);
         bus_assert_return(member_name_is_valid(member), -EINVAL, error);
         bus_assert_return(ret, -EINVAL, error);
@@ -458,6 +466,7 @@ _public_ int sd_bus_set_property(
         int r;
 
         bus_assert_return(bus, -EINVAL, error);
+        bus_assert_return(bus = bus_resolve(bus), -ENOPKG, error);
         bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error);
         bus_assert_return(member_name_is_valid(member), -EINVAL, error);
         bus_assert_return(signature_is_single(type, false), -EINVAL, error);
diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index 73127dfe02..62c34d9312 100644
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -585,14 +585,13 @@ _public_ int sd_bus_message_new(
                 sd_bus_message **m,
                 uint8_t type) {
 
-        sd_bus_message *t;
-
         assert_return(bus, -ENOTCONN);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
         assert_return(bus->state != BUS_UNSET, -ENOTCONN);
         assert_return(m, -EINVAL);
         assert_return(type < _SD_BUS_MESSAGE_TYPE_MAX, -EINVAL);
 
-        t = malloc0(ALIGN(sizeof(sd_bus_message)) + sizeof(struct bus_header));
+        sd_bus_message *t = malloc0(ALIGN(sizeof(sd_bus_message)) + sizeof(struct bus_header));
         if (!t)
                 return -ENOMEM;
 
@@ -623,6 +622,7 @@ _public_ int sd_bus_message_new_signal(
         int r;
 
         assert_return(bus, -ENOTCONN);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
         assert_return(bus->state != BUS_UNSET, -ENOTCONN);
         assert_return(object_path_is_valid(path), -EINVAL);
         assert_return(interface_name_is_valid(interface), -EINVAL);
@@ -663,6 +663,7 @@ _public_ int sd_bus_message_new_method_call(
         int r;
 
         assert_return(bus, -ENOTCONN);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
         assert_return(bus->state != BUS_UNSET, -ENOTCONN);
         assert_return(!destination || service_name_is_valid(destination), -EINVAL);
         assert_return(object_path_is_valid(path), -EINVAL);
diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c
index e45334c83f..5cbd01594c 100644
--- a/src/libsystemd/sd-bus/sd-bus.c
+++ b/src/libsystemd/sd-bus/sd-bus.c
@@ -504,7 +504,6 @@ static int synthesize_connected_signal(sd_bus *bus) {
 }
 
 void bus_set_state(sd_bus *bus, enum bus_state state) {
-
         static const char * const table[_BUS_STATE_MAX] = {
                 [BUS_UNSET] = "UNSET",
                 [BUS_WATCH_BIND] = "WATCH_BIND",
@@ -1899,9 +1898,10 @@ _public_ int sd_bus_send(sd_bus *bus, sd_bus_message *_m, uint64_t *cookie) {
 
         assert_return(m, -EINVAL);
 
-        if (!bus)
-                bus = m->bus;
-
+        if (bus)
+                assert_return(bus = bus_resolve(bus), -ENOPKG);
+        else
+                assert_return(bus = m->bus, -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
         if (!BUS_IS_OPEN(bus->state))
@@ -1983,9 +1983,10 @@ _public_ int sd_bus_send_to(sd_bus *bus, sd_bus_message *m, const char *destinat
 
         assert_return(m, -EINVAL);
 
-        if (!bus)
-                bus = m->bus;
-
+        if (bus)
+                assert_return(bus = bus_resolve(bus), -ENOPKG);
+        else
+                assert_return(bus = m->bus, -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
         if (!BUS_IS_OPEN(bus->state))
@@ -2048,9 +2049,10 @@ _public_ int sd_bus_call_async(
         assert_return(m->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
         assert_return(!m->sealed || (!!callback == !(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)), -EINVAL);
 
-        if (!bus)
-                bus = m->bus;
-
+        if (bus)
+                assert_return(bus = bus_resolve(bus), -ENOPKG);
+        else
+                assert_return(bus = m->bus, -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
         if (!BUS_IS_OPEN(bus->state))
@@ -2154,9 +2156,10 @@ _public_ int sd_bus_call(
         bus_assert_return(!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED), -EINVAL, error);
         bus_assert_return(!bus_error_is_dirty(error), -EINVAL, error);
 
-        if (!bus)
-                bus = m->bus;
-
+        if (bus)
+                assert_return(bus = bus_resolve(bus), -ENOPKG);
+        else
+                assert_return(bus = m->bus, -ENOTCONN);
         bus_assert_return(!bus_pid_changed(bus), -ECHILD, error);
 
         if (!BUS_IS_OPEN(bus->state)) {
@@ -2283,7 +2286,6 @@ fail:
 }
 
 _public_ int sd_bus_get_fd(sd_bus *bus) {
-
         assert_return(bus, -EINVAL);
         assert_return(bus = bus_resolve(bus), -ENOPKG);
         assert_return(bus->input_fd == bus->output_fd, -EPERM);
@@ -3674,31 +3676,31 @@ _public_ int sd_bus_detach_event(sd_bus *bus) {
 }
 
 _public_ sd_event* sd_bus_get_event(sd_bus *bus) {
-        assert_return(bus, NULL);
+        assert_return(bus = bus_resolve(bus), NULL);
 
         return bus->event;
 }
 
 _public_ sd_bus_message* sd_bus_get_current_message(sd_bus *bus) {
-        assert_return(bus, NULL);
+        assert_return(bus = bus_resolve(bus), NULL);
 
         return bus->current_message;
 }
 
 _public_ sd_bus_slot* sd_bus_get_current_slot(sd_bus *bus) {
-        assert_return(bus, NULL);
+        assert_return(bus = bus_resolve(bus), NULL);
 
         return bus->current_slot;
 }
 
 _public_ sd_bus_message_handler_t sd_bus_get_current_handler(sd_bus *bus) {
-        assert_return(bus, NULL);
+        assert_return(bus = bus_resolve(bus), NULL);
 
         return bus->current_handler;
 }
 
 _public_ void* sd_bus_get_current_userdata(sd_bus *bus) {
-        assert_return(bus, NULL);
+        assert_return(bus = bus_resolve(bus), NULL);
 
         return bus->current_userdata;
 }
@@ -4015,7 +4017,6 @@ _public_ int sd_bus_get_scope(sd_bus *bus, const char **scope) {
 }
 
 _public_ int sd_bus_get_address(sd_bus *bus, const char **address) {
-
         assert_return(bus, -EINVAL);
         assert_return(bus = bus_resolve(bus), -ENOPKG);
         assert_return(address, -EINVAL);