diff --git a/test/device_map_test.rb b/test/device_map_test.rb
index d247e57b1..bca724b6f 100644
--- a/test/device_map_test.rb
+++ b/test/device_map_test.rb
@@ -60,16 +60,7 @@
 
     it "limits number of disks in device map to 8" do
       # simple mock getting disks from partition as it need initialized libstorage
-      allow(Yast::Storage).to receive(:GetDiskPartition) do |partition|
-        if partition == "/dev/system/root"
-          disk = "/dev/system"
-          number = "system"
-        else
-          number = partition[/(\d+)$/, 1]
-          disk = partition[0..-(number.size + 1)]
-        end
-        { "disk" => disk, "nr" => number }
-      end
+      mock_disk_partition
 
       target_map_stub("many_disks.rb")