diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index be81a42..cf5a423 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -454,7 +454,8 @@ class TestSingleTransaction(iotests.QMPTestCase):
 
 class TestDriveCompression(iotests.QMPTestCase):
     image_len = 64 * 1024 * 1024 # MB
-    outfmt = 'qcow2'
+    fmt_supports_compression = [{'type': 'qcow2', 'args': ()},
+                                {'type': 'vmdk', 'args': ('-o', 'subformat=streamOptimized')}]
 
     def setUp(self):
         # Write data to the image so we can compare later
@@ -464,12 +465,6 @@ class TestDriveCompression(iotests.QMPTestCase):
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0x22 162k 32k', test_img)
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0x33 67043328 64k', test_img)
 
-        qemu_img('create', '-f', TestDriveCompression.outfmt, blockdev_target_img,
-                 str(TestDriveCompression.image_len))
-        self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img,
-                                                             format=TestDriveCompression.outfmt)
-        self.vm.launch()
-
     def tearDown(self):
         self.vm.shutdown()
         os.remove(test_img)
@@ -479,7 +474,18 @@ class TestDriveCompression(iotests.QMPTestCase):
         except OSError:
             pass
 
-    def do_test_compress_complete(self, cmd, **args):
+    def do_prepare_drives(self, fmt, args):
+        self.vm = iotests.VM().add_drive(test_img)
+
+        qemu_img('create', '-f', fmt, blockdev_target_img,
+                 str(TestDriveCompression.image_len), *args)
+        self.vm.add_drive(blockdev_target_img, format=fmt)
+
+        self.vm.launch()
+
+    def do_test_compress_complete(self, cmd, format, **args):
+        self.do_prepare_drives(format['type'], format['args'])
+
         self.assert_no_active_block_jobs()
 
         result = self.vm.qmp(cmd, device='drive0', sync='full', compress=True, **args)
@@ -489,16 +495,21 @@ class TestDriveCompression(iotests.QMPTestCase):
 
         self.vm.shutdown()
         self.assertTrue(iotests.compare_images(test_img, blockdev_target_img,
-                                               iotests.imgfmt, TestDriveCompression.outfmt),
+                                               iotests.imgfmt, format['type']),
                         'target image does not match source after backup')
 
     def test_complete_compress_drive_backup(self):
-        self.do_test_compress_complete('drive-backup', target=blockdev_target_img, mode='existing')
+        for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_complete('drive-backup', format,
+                                           target=blockdev_target_img, mode='existing')
 
     def test_complete_compress_blockdev_backup(self):
-        self.do_test_compress_complete('blockdev-backup', target='drive1')
+        for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_complete('blockdev-backup', format, target='drive1')
+
+    def do_test_compress_cancel(self, cmd, format, **args):
+        self.do_prepare_drives(format['type'], format['args'])
 
-    def do_test_compress_cancel(self, cmd, **args):
         self.assert_no_active_block_jobs()
 
         result = self.vm.qmp(cmd, device='drive0', sync='full', compress=True, **args)
@@ -507,13 +518,20 @@ class TestDriveCompression(iotests.QMPTestCase):
         event = self.cancel_and_wait()
         self.assert_qmp(event, 'data/type', 'backup')
 
+        self.vm.shutdown()
+
     def test_compress_cancel_drive_backup(self):
-        self.do_test_compress_cancel('drive-backup', target=blockdev_target_img, mode='existing')
+        for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_cancel('drive-backup', format,
+                                         target=blockdev_target_img, mode='existing')
 
     def test_compress_cancel_blockdev_backup(self):
-        self.do_test_compress_cancel('blockdev-backup', target='drive1')
+       for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_cancel('blockdev-backup', format, target='drive1')
+
+    def do_test_compress_pause(self, cmd, format, **args):
+        self.do_prepare_drives(format['type'], format['args'])
 
-    def do_test_compress_pause(self, cmd, **args):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
@@ -539,14 +557,17 @@ class TestDriveCompression(iotests.QMPTestCase):
 
         self.vm.shutdown()
         self.assertTrue(iotests.compare_images(test_img, blockdev_target_img,
-                                               iotests.imgfmt, TestDriveCompression.outfmt),
+                                               iotests.imgfmt, format['type']),
                         'target image does not match source after backup')
 
     def test_compress_pause_drive_backup(self):
-        self.do_test_compress_pause('drive-backup', target=blockdev_target_img, mode='existing')
+        for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_pause('drive-backup', format,
+                                        target=blockdev_target_img, mode='existing')
 
     def test_compress_pause_blockdev_backup(self):
-        self.do_test_compress_pause('blockdev-backup', target='drive1')
+        for format in TestDriveCompression.fmt_supports_compression:
+            self.do_test_compress_pause('blockdev-backup', format, target='drive1')
 
 if __name__ == '__main__':
     iotests.main(supported_fmts=['raw', 'qcow2'])
