diff --git a/src/login/inhibit.c b/src/login/inhibit.c
index 9d0d97c22c..75dba8c08f 100644
--- a/src/login/inhibit.c
+++ b/src/login/inhibit.c
@@ -61,7 +61,7 @@ static int print_inhibitors(sd_bus *bus) {
 
         pager_open(arg_pager_flags);
 
-        r = bus_call_method(bus, bus_login_mgr, "ListInhibitors", &error, &reply, "");
+        r = bus_call_method(bus, bus_login_mgr, "ListInhibitors", &error, &reply, NULL);
         if (r < 0)
                 return log_error_errno(r, "Could not get active inhibitors: %s", bus_error_message(&error, r));
 
diff --git a/src/login/test-inhibit.c b/src/login/test-inhibit.c
index b2a5dfecc8..f59cca8fed 100644
--- a/src/login/test-inhibit.c
+++ b/src/login/test-inhibit.c
@@ -35,7 +35,7 @@ static void print_inhibitors(sd_bus *bus) {
         unsigned n = 0;
         int r;
 
-        r = bus_call_method(bus, bus_login_mgr, "ListInhibitors", &error, &reply, "");
+        r = bus_call_method(bus, bus_login_mgr, "ListInhibitors", &error, &reply, NULL);
         assert_se(r >= 0);
 
         r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "(ssssuu)");
diff --git a/src/login/test-session-properties.c b/src/login/test-session-properties.c
index 48aa21abef..b5b5f60eaa 100644
--- a/src/login/test-session-properties.c
+++ b/src/login/test-session-properties.c
@@ -57,7 +57,7 @@ TEST(set_type) {
 
         /* Type is reset to the original value when we release control of the session */
         assert_se(!streq(type, "tty"));
-        assert_se(bus_call_method(bus, &session, "ReleaseControl", NULL, NULL, "") >= 0);
+        assert_se(bus_call_method(bus, &session, "ReleaseControl", NULL, NULL, NULL) >= 0);
         type = mfree(type);
         assert_se(bus_get_property_string(bus, &session, "Type", NULL, &type) >= 0);
         assert_se(streq(type, "tty"));