diff --git a/src/company_cmd.cpp b/src/company_cmd.cpp
--- a/src/company_cmd.cpp
+++ b/src/company_cmd.cpp
@@ -188,7 +188,7 @@ void InvalidateCompanyWindows(const Comp
 
 /**
  * Verify whether the company can pay the bill.
- * @param cost [inout] Money to pay, is changed to an error if the company does not have enough money.
+ * @param[in,out] cost Money to pay, is changed to an error if the company does not have enough money.
  * @return Function returns \c true if the company has enough money, else it returns \c false.
  */
 bool CheckCompanyHasMoney(CommandCost &cost)