diff --git a/api/src/com/cloud/api/commands/UpdateVMCmd.java b/api/src/com/cloud/api/commands/UpdateVMCmd.java
index 49a0e886fe4..b751c76e06d 100644
--- a/api/src/com/cloud/api/commands/UpdateVMCmd.java
+++ b/api/src/com/cloud/api/commands/UpdateVMCmd.java
@@ -25,11 +25,14 @@ import com.cloud.user.Account;
 import com.cloud.user.UserContext;
 import com.cloud.uservm.UserVm;
 
-@Implementation(description="Updates parameters of a virtual machine.", responseObject=UserVmResponse.class)
-public class UpdateVMCmd extends BaseCmd{
-    public static final Logger s_logger = Logger.getLogger(UpdateVMCmd.class.getName());
-    private static final String s_name = "updatevirtualmachineresponse";
 
+@Implementation(description="Updates properties of a virtual machine. The VM has to be stopped and restarted for the " +
+		"new properties to take effect. UpdateVirtualMachine does not first check whether the VM is stopped. " +
+		"Therefore, stop the VM manually before issuing this call.", responseObject=UserVmResponse.class)
+public class UpdateVMCmd extends BaseCmd{
+    public static final Logger s_logger = Logger.getLogger(UpdateVMCmd.class.getName());
+    private static final String s_name = "updatevirtualmachineresponse";
+
     /////////////////////////////////////////////////////
     //////////////// API parameters /////////////////////
     /////////////////////////////////////////////////////