diff --git a/src/strings.cpp b/src/strings.cpp
index fc51e1051e..f2499e1ea3 100644
--- a/src/strings.cpp
+++ b/src/strings.cpp
@@ -1050,6 +1050,8 @@ uint ConvertDisplayQuantityToCargoQuantity(CargoID cargo, uint quantity)
 	return quantity;
 }
 
+static std::vector<const char *> _game_script_raw_strings;
+
 /**
  * Parse most format codes within a string and write the result to a buffer.
  * @param buff    The buffer to write the final string to.
@@ -1183,6 +1185,7 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 
 						sub_args_need_free[i] = true;
 						sub_args.SetParam(i++, (uint64)(size_t)g);
+						_game_script_raw_strings.push_back(g);
 					}
 				}
 				/* If we didn't error out, we can actually print the string. */
@@ -1192,7 +1195,10 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 				}
 
 				for (int i = 0; i < 20; i++) {
-					if (sub_args_need_free[i]) free((void *)sub_args.GetParam(i));
+					if (sub_args_need_free[i]) {
+						free((void *)sub_args.GetParam(i));
+						_game_script_raw_strings.pop_back();
+					}
 				}
 				break;
 			}
@@ -1297,6 +1303,10 @@ static char *FormatString(char *buff, const char *str_arg, StringParameters *arg
 
 			case SCC_RAW_STRING_POINTER: { // {RAW_STRING}
 				const char *raw_string = (const char *)(size_t)args->GetInt64(SCC_RAW_STRING_POINTER);
+				if (game_script && std::find(_game_script_raw_strings.begin(), _game_script_raw_strings.end(), raw_string) == _game_script_raw_strings.end()) {
+					buff = strecat(buff, "(invalid RAW_STRING parameter)", last);
+					break;
+				}
 				buff = FormatString(buff, raw_string, args, last);
 				break;
 			}