diff --git a/qubes/storage/__init__.py b/qubes/storage/__init__.py
index 2d070f99..d82fe6ec 100644
--- a/qubes/storage/__init__.py
+++ b/qubes/storage/__init__.py
@@ -251,7 +251,7 @@ class Pool(object):
     def __xml__(self):
         return lxml.etree.Element('pool', **self.config)
 
-    def create(self, volume, source_volume):
+    def create(self, volume, source_volume=None):
         ''' Create the given volume on disk or copy from provided
             `source_volume`.
         '''
diff --git a/qubes/storage/kernels.py b/qubes/storage/kernels.py
index f524849c..31477d88 100644
--- a/qubes/storage/kernels.py
+++ b/qubes/storage/kernels.py
@@ -67,7 +67,7 @@ class LinuxKernel(Pool):
     def clone(self, source, target):
         return target
 
-    def create(self, volume, source_volume):
+    def create(self, volume, source_volume=None):
         return volume
 
     def commit_template_changes(self, volume):