diff --git a/data-access/engine/src/common/include/ast4vl.hpp b/data-access/engine/src/common/include/ast4vl.hpp
index db7542312b93808d205688973be05657cb46c2c1..7c40f8a75c1c5bcb63d02718e93339d266bd3113 100644
--- a/data-access/engine/src/common/include/ast4vl.hpp
+++ b/data-access/engine/src/common/include/ast4vl.hpp
@@ -25,7 +25,7 @@ struct double_xy
 {
    double x;
    double y;
-   unsigned char type;
+   /*unsigned*/ char type;
 };
 
 struct overlap_ranges