diff --git a/src/table/newgrf_debug_data.h b/src/table/newgrf_debug_data.h
--- a/src/table/newgrf_debug_data.h
+++ b/src/table/newgrf_debug_data.h
@@ -12,11 +12,11 @@
 #include "../newgrf_roadtype.h"
 
 /* Helper for filling property tables */
-#define NIP(prop, base, variable, type, name) { name, (ptrdiff_t)cpp_offsetof(base, variable), cpp_sizeof(base, variable), prop, type }
+#define NIP(prop, base, variable, type, name) { name, [] (const void *b) -> const void * { return std::addressof(static_cast<const base *>(b)->variable); }, cpp_sizeof(base, variable), prop, type }
 #define NIP_END() { nullptr, 0, 0, 0, 0 }
 
 /* Helper for filling callback tables */
-#define NIC(cb_id, base, variable, bit) { #cb_id, (ptrdiff_t)cpp_offsetof(base, variable), cpp_sizeof(base, variable), bit, cb_id }
+#define NIC(cb_id, base, variable, bit) { #cb_id, [] (const void *b) -> const void * { return std::addressof(static_cast<const base *>(b)->variable); }, cpp_sizeof(base, variable), bit, cb_id }
 #define NIC_END() { nullptr, 0, 0, 0, 0 }
 
 /* Helper for filling variable tables */