diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1543,7 +1543,7 @@ CommandCost CmdFoundTown(TileIndex tile,
 		if (!VerifyTownName(townnameparts, &par)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	} else {
 		/* If name is not empty, it has to be unique custom name */
-		if (strlen(text) >= MAX_LENGTH_TOWN_NAME_BYTES) return CMD_ERROR;
+		if (Utf8StringLength(text) >= MAX_LENGTH_TOWN_NAME_CHARS) return CMD_ERROR;
 		if (!IsUniqueTownName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}
 
@@ -2295,7 +2295,7 @@ CommandCost CmdRenameTown(TileIndex tile
 	bool reset = StrEmpty(text);
 
 	if (!reset) {
-		if (strlen(text) >= MAX_LENGTH_TOWN_NAME_BYTES) return CMD_ERROR;
+		if (Utf8StringLength(text) >= MAX_LENGTH_TOWN_NAME_CHARS) return CMD_ERROR;
 		if (!IsUniqueTownName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}