diff --git a/utils/fasm/src/fasm.h b/utils/fasm/src/fasm.h
index 3e92a5f..28ab1c7 100644
--- a/utils/fasm/src/fasm.h
+++ b/utils/fasm/src/fasm.h
@@ -85,6 +85,7 @@
       std::ostream& os_;
 
       t_pb_graph_node *root_clb_;
+      bool current_blk_has_prefix_;
       t_physical_tile_type_ptr blk_type_;
       std::string blk_prefix_;
       std::string clb_prefix_;