diff --git a/_constraints b/_constraints
index 7a401ec..a42ffec 100644
--- a/_constraints
+++ b/_constraints
@@ -6,7 +6,7 @@
       <size unit="G">4</size>
     </memory>
     <disk>
-      <size unit="G">40</size>
+      <size unit="G">20</size>
     </disk>
   </hardware>
   <overwrite>