diff --git a/_constraints b/_constraints
index b1c6bb0..2846a6a 100644
--- a/_constraints
+++ b/_constraints
@@ -48,4 +48,16 @@
       </disk>
     </hardware>
   </overwrite>
+  <overwrite>
+    <conditions>
+      <arch>s390x</arch>
+      <arch>ppc64</arch>
+      <arch>ppc64le</arch>
+    </conditions>
+    <hardware>
+      <disk>
+        <size unit="G">25</size>
+      </disk>
+    </hardware>
+  </overwrite>
 </constraints>