diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 8ce2373cf5..952a524ec7 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -34,7 +34,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         iotests.create_image(backing_img, TestSingleDrive.image_len)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, mid_img)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % mid_img, test_img)
-        qemu_io('-c', 'write -P 0x1 0 512', backing_img)
+        qemu_io('-f', 'raw', '-c', 'write -P 0x1 0 512', backing_img)
         self.vm = iotests.VM().add_drive("blkdebug::" + test_img)
         self.vm.launch()
 
@@ -55,8 +55,8 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
         self.vm.shutdown()
 
-        self.assertEqual(qemu_io('-c', 'map', backing_img),
-                         qemu_io('-c', 'map', test_img),
+        self.assertEqual(qemu_io('-f', 'raw', '-c', 'map', backing_img),
+                         qemu_io('-f', iotests.imgfmt, '-c', 'map', test_img),
                          'image file map does not match backing file after streaming')
 
     def test_stream_pause(self):
@@ -86,8 +86,8 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
         self.vm.shutdown()
 
-        self.assertEqual(qemu_io('-c', 'map', backing_img),
-                         qemu_io('-c', 'map', test_img),
+        self.assertEqual(qemu_io('-f', 'raw', '-c', 'map', backing_img),
+                         qemu_io('-f', iotests.imgfmt, '-c', 'map', test_img),
                          'image file map does not match backing file after streaming')
 
     def test_stream_partial(self):
@@ -101,8 +101,8 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
         self.vm.shutdown()
 
-        self.assertEqual(qemu_io('-c', 'map', mid_img),
-                         qemu_io('-c', 'map', test_img),
+        self.assertEqual(qemu_io('-f', iotests.imgfmt, '-c', 'map', mid_img),
+                         qemu_io('-f', iotests.imgfmt, '-c', 'map', test_img),
                          'image file map does not match backing file after streaming')
 
     def test_device_not_found(self):
@@ -359,9 +359,9 @@ class TestStreamStop(iotests.QMPTestCase):
 
     def setUp(self):
         qemu_img('create', backing_img, str(TestStreamStop.image_len))
-        qemu_io('-c', 'write -P 0x1 0 32M', backing_img)
+        qemu_io('-f', 'raw', '-c', 'write -P 0x1 0 32M', backing_img)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, test_img)
-        qemu_io('-c', 'write -P 0x1 32M 32M', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0x1 32M 32M', test_img)
         self.vm = iotests.VM().add_drive("blkdebug::" + test_img)
         self.vm.launch()
 
@@ -388,9 +388,9 @@ class TestSetSpeed(iotests.QMPTestCase):
 
     def setUp(self):
         qemu_img('create', backing_img, str(TestSetSpeed.image_len))
-        qemu_io('-c', 'write -P 0x1 0 32M', backing_img)
+        qemu_io('-f', 'raw', '-c', 'write -P 0x1 0 32M', backing_img)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, test_img)
-        qemu_io('-c', 'write -P 0x1 32M 32M', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0x1 32M 32M', test_img)
         self.vm = iotests.VM().add_drive('blkdebug::' + test_img)
         self.vm.launch()
 
diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040
index 2b432ad7a1..ea2f98e51d 100755
--- a/tests/qemu-iotests/040
+++ b/tests/qemu-iotests/040
@@ -76,8 +76,8 @@ class TestSingleDrive(ImageCommitTestCase):
         iotests.create_image(backing_img, self.image_len)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, mid_img)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % mid_img, test_img)
-        qemu_io('-c', 'write -P 0xab 0 524288', backing_img)
-        qemu_io('-c', 'write -P 0xef 524288 524288', mid_img)
+        qemu_io('-f', 'raw', '-c', 'write -P 0xab 0 524288', backing_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xef 524288 524288', mid_img)
         self.vm = iotests.VM().add_drive(test_img)
         self.vm.launch()
 
@@ -89,8 +89,8 @@ class TestSingleDrive(ImageCommitTestCase):
 
     def test_commit(self):
         self.run_commit_test(mid_img, backing_img)
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
 
     def test_device_not_found(self):
         result = self.vm.qmp('block-commit', device='nonexistent', top='%s' % mid_img)
@@ -116,13 +116,13 @@ class TestSingleDrive(ImageCommitTestCase):
 
     def test_top_is_active(self):
         self.run_commit_test(test_img, backing_img, need_ready=True)
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
 
     def test_top_is_default_active(self):
         self.run_default_commit_test()
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xab 0 524288', backing_img).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xef 524288 524288', backing_img).find("verification failed"))
 
     def test_top_and_base_reversed(self):
         self.assert_no_active_block_jobs()
@@ -159,8 +159,8 @@ class TestRelativePaths(ImageCommitTestCase):
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % self.mid_img_abs, self.test_img)
         qemu_img('rebase', '-u', '-b', self.backing_img, self.mid_img_abs)
         qemu_img('rebase', '-u', '-b', self.mid_img, self.test_img)
-        qemu_io('-c', 'write -P 0xab 0 524288', self.backing_img_abs)
-        qemu_io('-c', 'write -P 0xef 524288 524288', self.mid_img_abs)
+        qemu_io('-f', 'raw', '-c', 'write -P 0xab 0 524288', self.backing_img_abs)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xef 524288 524288', self.mid_img_abs)
         self.vm = iotests.VM().add_drive(self.test_img)
         self.vm.launch()
 
@@ -179,8 +179,8 @@ class TestRelativePaths(ImageCommitTestCase):
 
     def test_commit(self):
         self.run_commit_test(self.mid_img, self.backing_img)
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xab 0 524288', self.backing_img_abs).find("verification failed"))
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xef 524288 524288', self.backing_img_abs).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xab 0 524288', self.backing_img_abs).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xef 524288 524288', self.backing_img_abs).find("verification failed"))
 
     def test_device_not_found(self):
         result = self.vm.qmp('block-commit', device='nonexistent', top='%s' % self.mid_img)
@@ -206,8 +206,8 @@ class TestRelativePaths(ImageCommitTestCase):
 
     def test_top_is_active(self):
         self.run_commit_test(self.test_img, self.backing_img)
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xab 0 524288', self.backing_img_abs).find("verification failed"))
-        self.assertEqual(-1, qemu_io('-c', 'read -P 0xef 524288 524288', self.backing_img_abs).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xab 0 524288', self.backing_img_abs).find("verification failed"))
+        self.assertEqual(-1, qemu_io('-f', 'raw', '-c', 'read -P 0xef 524288 524288', self.backing_img_abs).find("verification failed"))
 
     def test_top_and_base_reversed(self):
         self.assert_no_active_block_jobs()
@@ -223,8 +223,8 @@ class TestSetSpeed(ImageCommitTestCase):
         qemu_img('create', backing_img, str(TestSetSpeed.image_len))
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, mid_img)
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % mid_img, test_img)
-        qemu_io('-c', 'write -P 0x1 0 512', test_img)
-        qemu_io('-c', 'write -P 0xef 524288 524288', mid_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0x1 0 512', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xef 524288 524288', mid_img)
         self.vm = iotests.VM().add_drive(test_img)
         self.vm.launch()
 
diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index 451b67ddfb..0872444811 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -34,10 +34,10 @@ class TestSingleDrive(iotests.QMPTestCase):
     def setUp(self):
         # Write data to the image so we can compare later
         qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestSingleDrive.image_len))
-        qemu_io('-c', 'write -P0x5d 0 64k', test_img)
-        qemu_io('-c', 'write -P0xd5 1M 32k', test_img)
-        qemu_io('-c', 'write -P0xdc 32M 124k', test_img)
-        qemu_io('-c', 'write -P0xdc 67043328 64k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0x5d 0 64k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xd5 1M 32k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 32M 124k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 67043328 64k', test_img)
 
         self.vm = iotests.VM().add_drive(test_img)
         self.vm.launch()
@@ -115,7 +115,7 @@ class TestSetSpeed(iotests.QMPTestCase):
 
     def setUp(self):
         qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestSetSpeed.image_len))
-        qemu_io('-c', 'write -P1 0 512', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P1 0 512', test_img)
         self.vm = iotests.VM().add_drive(test_img)
         self.vm.launch()
 
@@ -186,10 +186,10 @@ class TestSingleTransaction(iotests.QMPTestCase):
 
     def setUp(self):
         qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestSingleTransaction.image_len))
-        qemu_io('-c', 'write -P0x5d 0 64k', test_img)
-        qemu_io('-c', 'write -P0xd5 1M 32k', test_img)
-        qemu_io('-c', 'write -P0xdc 32M 124k', test_img)
-        qemu_io('-c', 'write -P0xdc 67043328 64k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0x5d 0 64k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xd5 1M 32k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 32M 124k', test_img)
+        qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 67043328 64k', test_img)
 
         self.vm = iotests.VM().add_drive(test_img)
         self.vm.launch()