diff --git a/libs/libarchfpga/src/physical_types.h b/libs/libarchfpga/src/physical_types.h
index 81eb27d..736d6ff 100644
--- a/libs/libarchfpga/src/physical_types.h
+++ b/libs/libarchfpga/src/physical_types.h
@@ -56,11 +56,11 @@
 struct t_mode;
 struct t_pb_graph_node_power;
 struct t_port;
-struct t_pb_graph_node;
+class t_pb_graph_node;
 struct t_pin_to_pin_annotation;
 struct t_interconnect;
-struct t_pb_graph_pin;
-struct t_pb_graph_edge;
+class t_pb_graph_pin;
+class t_pb_graph_edge;
 struct t_cluster_placement_primitive;
 struct t_arch;
 enum class e_sb_type;