diff --git a/src/api/vm.coffee b/src/api/vm.coffee
index cb70dcb10..252203462 100644
--- a/src/api/vm.coffee
+++ b/src/api/vm.coffee
@@ -383,7 +383,9 @@ exports.restart = ->
     # Attempts a clean reboot.
     xapi.call 'VM.clean_reboot', VM.ref
   catch error
-    throw error unless error[0] is 'VM_MISSING_PV_DRIVERS'
+    return unless error[0] is 'VM_MISSING_PV_DRIVERS'
+
+    @throw 'INVALID_PARAMS' unless force
 
     xapi.call 'VM.hard_reboot', VM.ref
 
@@ -430,7 +432,9 @@ exports.stop = ->
     # Attempts a clean shutdown.
     xapi.call 'VM.clean_shutdown', VM.ref
   catch error
-    throw error unless error[0] is 'VM_MISSING_PV_DRIVERS'
+    return unless error[0] is 'VM_MISSING_PV_DRIVERS'
+
+    @throw 'INVALID_PARAMS' unless force
 
     xapi.call 'VM.hard_shutdown', VM.ref