diff --git a/plugins/proto/RemoteFortressReader.proto b/plugins/proto/RemoteFortressReader.proto
index 433a247ae..cb7acca07 100644
--- a/plugins/proto/RemoteFortressReader.proto
+++ b/plugins/proto/RemoteFortressReader.proto
@@ -267,7 +267,7 @@ message Item
     optional MatPair type = 5;
     optional MatPair material = 6;
     optional ColorDefinition dye = 7;
-	optional int32 stack_size = 8;
+    optional int32 stack_size = 8;
 }
 
 message MapBlock