diff --git a/nixos/lib/test-driver/Machine.pm b/nixos/lib/test-driver/Machine.pm
index 99810f87750d..6d3ffa173593 100644
--- a/nixos/lib/test-driver/Machine.pm
+++ b/nixos/lib/test-driver/Machine.pm
@@ -495,7 +495,7 @@ sub waitForX {
     my ($self, $regexp) = @_;
     $self->nest("waiting for the X11 server", sub {
         retry sub {
-            my ($status, $out) = $self->execute("journalctl -bu systemd-logind | grep Linked");
+            my ($status, $out) = $self->execute("journalctl -b -u systemd-logind | grep Linked");
             return 0 if $status != 0;
             ($status, $out) = $self->execute("xwininfo -root > /dev/null 2>&1");
             return 1 if $status == 0;