diff --git a/spice.proto b/spice.proto
index 240ed05..0d970da 100644
--- a/spice.proto
+++ b/spice.proto
@@ -529,7 +529,7 @@ struct Brush {
         uint32 color;
     case PATTERN:
         Pattern pattern;
-    } u @fixedsize;
+    } u;
 };
 
 struct QMask {