diff --git a/src/ai/ai_instance.cpp b/src/ai/ai_instance.cpp
--- a/src/ai/ai_instance.cpp
+++ b/src/ai/ai_instance.cpp
@@ -353,7 +353,7 @@ void AIInstance::CollectGarbage()
 
 /* static */ AIStorage *AIInstance::GetStorage()
 {
-	assert(IsValidCompanyID(_current_company) && !IsHumanCompany(_current_company));
+	assert(Company::IsValidID(_current_company) && !IsHumanCompany(_current_company));
 	return Company::Get(_current_company)->ai_instance->storage;
 }