diff --git a/nova/tests/unit/virt/libvirt/test_utils.py b/nova/tests/unit/virt/libvirt/test_utils.py
index 13a5e8ee8c79..16633a347a19 100644
--- a/nova/tests/unit/virt/libvirt/test_utils.py
+++ b/nova/tests/unit/virt/libvirt/test_utils.py
@@ -649,8 +649,8 @@ disk size: 4.4M
         target = 't.qcow2'
         self.executes = []
         expected_commands = [('qemu-img', 'convert', '-O', 'raw',
-                              't.qcow2.part', 't.qcow2.converted',
-                              '-f', 'qcow2'),
+                              '-f', 'qcow2',
+                              't.qcow2.part', 't.qcow2.converted'),
                              ('rm', 't.qcow2.part'),
                              ('mv', 't.qcow2.converted', 't.qcow2')]
         images.fetch_to_raw(context, image_id, target)
diff --git a/nova/virt/images.py b/nova/virt/images.py
index 3a4fb93df945..33b247005926 100644
--- a/nova/virt/images.py
+++ b/nova/virt/images.py
@@ -96,9 +96,10 @@ def convert_image_unsafe(source, dest, out_format, run_as_root=False):
 
 
 def _convert_image(source, dest, in_format, out_format, run_as_root):
-    cmd = ('qemu-img', 'convert', '-O', out_format, source, dest)
+    cmd = ('qemu-img', 'convert', '-O', out_format)
     if in_format is not None:
         cmd = cmd + ('-f', in_format)
+    cmd = cmd + (source, dest)
     try:
         utils.execute(*cmd, run_as_root=run_as_root)
     except processutils.ProcessExecutionError as exp: