diff --git a/src/util/00-mesa-defaults.conf b/src/util/00-mesa-defaults.conf
index 2a8be406657..148e756221c 100644
--- a/src/util/00-mesa-defaults.conf
+++ b/src/util/00-mesa-defaults.conf
@@ -1202,6 +1202,7 @@ TODO: document the other workarounds.
         <!-- Disable FCV optimization for Unreal Engine 5.1 workloads. -->
         <engine engine_name_match="UnrealEngine5.1">
             <option name="anv_disable_fcv" value="true" />
+            <option name="anv_assume_full_subgroups" value="16" />
         </engine>
     </device>
     <device driver="dzn">