Index: src/engine.cpp
===================================================================
--- src/engine.cpp	(revision 27816)
+++ src/engine.cpp	(working copy)
@@ -1113,7 +1113,10 @@
 
 	/* Are there suffixes?
 	 * Note: This does not mean the suffixes are actually available for every consist at any time. */
-	if (HasBit(ei->callback_mask, CBM_VEHICLE_CARGO_SUFFIX)) return true;
+	if (HasBit(ei->callback_mask, CBM_VEHICLE_CARGO_SUFFIX)) {
+		uint16 cb = GetVehicleCallback(CBID_VEHICLE_CARGO_SUFFIX, 0, 0, engine, NULL);
+		return cb != CALLBACK_FAILED;
+	}
 
 	/* Is there any cargo except the default cargo? */
 	CargoID default_cargo = e->GetDefaultCargoType();
Index: src/vehicle_gui.cpp
===================================================================
--- src/vehicle_gui.cpp	(revision 27816)
+++ src/vehicle_gui.cpp	(working copy)
@@ -2404,6 +2404,26 @@
 	DoCommandP(v->tile, v->index, 0, _vehicle_command_translation_table[VCT_CMD_START_STOP][v->type], texteffect ? CcStartStopVehicle : NULL);
 }
 
+static bool IsVehiclePartRefittable(const Vehicle *v)
+{
+	const Engine *e = Engine::GetIfValid(v->engine_type);
+
+	if (e == NULL) return false;
+
+	if (!e->CanCarryCargo()) return false;
+
+	const EngineInfo *ei = &e->info;
+	if (ei->refit_mask == 0) return false;
+
+	if (HasBit(ei->callback_mask, CBM_VEHICLE_CARGO_SUFFIX)) {
+		uint16 cb = GetVehicleCallback(CBID_VEHICLE_CARGO_SUFFIX, 0, 0, v->engine_type, v);
+		return cb != CALLBACK_FAILED;
+	}
+
+	CargoID default_cargo = e->GetDefaultCargoType();
+	return default_cargo != CT_INVALID && ei->refit_mask != 1U << default_cargo;
+}
+
 /** Checks whether the vehicle may be refitted at the moment.*/
 static bool IsVehicleRefitable(const Vehicle *v)
 {
@@ -2410,7 +2430,7 @@
 	if (!v->IsStoppedInDepot()) return false;
 
 	do {
-		if (IsEngineRefittable(v->engine_type)) return true;
+		if (IsVehiclePartRefittable(v)) return true;
 	} while (v->IsGroundVehicle() && (v = v->Next()) != NULL);
 
 	return false;