diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index dab9ef728aefba75327a0b1e1fbe51a4ea1378a4..1c2ffbbec16ecf2d3925ae7c982d402fdffc74d0 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -4730,7 +4730,7 @@ class LUCreateInstance(LogicalUnit):
     # os verification
     result = self.rpc.call_os_get(pnode.name, self.op.os_type)
     result.Raise()
-    if not isinstance(result.data, objects.OS):
+    if not isinstance(result.data, objects.OS) or not result.data:
       raise errors.OpPrereqError("OS '%s' not in supported os list for"
                                  " primary node"  % self.op.os_type)