diff --git a/tools/python/xen/xend/XendDomain.py b/tools/python/xen/xend/XendDomain.py
index 48efcf7370..4e76acfdbe 100644
--- a/tools/python/xen/xend/XendDomain.py
+++ b/tools/python/xen/xend/XendDomain.py
@@ -480,8 +480,7 @@ class XendDomain:
         dominfo = self.domain_lookup(domid)
         maxmem = int(mem) * 1024
         try:
-            return xc.domain_setmaxmem(dominfo.getDomid(),
-                                       maxmem_kb = maxmem)
+            return xc.domain_setmaxmem(dominfo.getDomid(), maxmem)
         except Exception, ex:
             raise XendError(str(ex))