diff --git a/assets/win81x64.xml b/assets/win81x64.xml
index 0e1f2df..ac02ed4 100644
--- a/assets/win81x64.xml
+++ b/assets/win81x64.xml
@@ -20,13 +20,13 @@
             <CreatePartition wcm:action="add">
               <Order>1</Order>
               <Type>Primary</Type>
-              <Size>300</Size>
+              <Size>256</Size>
             </CreatePartition>
             <!-- System partition (ESP) -->
             <CreatePartition wcm:action="add">
               <Order>2</Order>
               <Type>EFI</Type>
-              <Size>100</Size>
+              <Size>128</Size>
             </CreatePartition>
             <!-- Microsoft reserved partition (MSR) -->
             <CreatePartition wcm:action="add">