diff --git a/src/script/api/script_rail.cpp b/src/script/api/script_rail.cpp
--- a/src/script/api/script_rail.cpp
+++ b/src/script/api/script_rail.cpp
@@ -195,7 +195,7 @@
 		int index = 0;
 		const StationSpec *spec = StationClass::GetByGrf(file->grfid, res, &index);
 		if (spec == nullptr) {
-			DEBUG(grf, 1, "%s returned an invalid station ID for 'AI construction/purchase selection (18)' callback", file->filename);
+			Debug(grf, 1, "{} returned an invalid station ID for 'AI construction/purchase selection (18)' callback", file->filename);
 		} else {
 			/* We might have gotten an usable station spec. Try to build it, but if it fails we'll fall back to the original station. */
 			if (ScriptObject::DoCommand(tile, p1, p2 | spec->cls_id | index << 8, CMD_BUILD_RAIL_STATION)) return true;