diff --git a/src/cargomonitor.cpp b/src/cargomonitor.cpp
--- a/src/cargomonitor.cpp
+++ b/src/cargomonitor.cpp
@@ -124,13 +124,13 @@ void AddCargoDelivery(CargoID cargo_type
 	if (src != INVALID_SOURCE) {
 		/* Handle pickup update. */
 		switch (src_type) {
-			case ST_INDUSTRY: {
+			case SourceType::Industry: {
 				CargoMonitorID num = EncodeCargoIndustryMonitor(company, cargo_type, src);
 				CargoMonitorMap::iterator iter = _cargo_pickups.find(num);
 				if (iter != _cargo_pickups.end()) iter->second += amount;
 				break;
 			}
-			case ST_TOWN: {
+			case SourceType::Town: {
 				CargoMonitorID num = EncodeCargoTownMonitor(company, cargo_type, src);
 				CargoMonitorMap::iterator iter = _cargo_pickups.find(num);
 				if (iter != _cargo_pickups.end()) iter->second += amount;