diff --git a/_constraints b/_constraints
index af6ef21..3fa17cc 100644
--- a/_constraints
+++ b/_constraints
@@ -1,7 +1,11 @@
+<?xml version="1.0"?>
 <constraints>
   <hardware>
-    <memory>
-      <size unit="G">2</size>
-    </memory>
+    <physicalmemory>
+      <size unit="M">2000</size>
+    </physicalmemory>
   </hardware>
+  <sandbox>kvm</sandbox>
+  <hostlabel exclude="true">SLOW_CPU</hostlabel>
 </constraints>
+