diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index 1c3fb148410..98e8142a0df 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -147,6 +147,9 @@ let
             or die "bad `hello' output";
       ''}
 
+      # Wait for hard disks to appear in /dev
+      $machine->succeed("udevadm settle");
+
       # Partition the disk.
       ${createPartitions}