diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index ff5de1cd10..a88dfb4a3f 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -986,6 +986,13 @@ class XendDomainInfo:
                   self.info['name_label'], str(self.domid), target)
         
         MiB = 1024 * 1024
+
+        if self.domid == 0:
+            dom0_min_mem = xoptions.get_dom0_min_mem()
+            memory_cur = self.get_memory_dynamic_max() / MiB
+            if target < memory_cur and dom0_min_mem > target:
+                raise XendError("memory_dynamic_max too small")
+
         self._safe_set_memory('memory_dynamic_min', target * MiB)
         self._safe_set_memory('memory_dynamic_max', target * MiB)