diff --git a/src/engine.cpp b/src/engine.cpp
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -487,7 +487,8 @@ static bool IsUniqueEngineName(const cha
  */
 CommandCost CmdRenameEngine(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
-	if (!IsEngineIndex(p1) || StrEmpty(_cmd_text)) return CMD_ERROR;
+	if (!IsEngineIndex(p1)) return CMD_ERROR;
+	if (StrEmpty(_cmd_text) || strlen(_cmd_text) >= MAX_LENGTH_ENGINE_NAME_BYTES) return CMD_ERROR;
 
 	if (!IsUniqueEngineName(_cmd_text)) return_cmd_error(STR_NAME_MUST_BE_UNIQUE);
 
diff --git a/src/group_cmd.cpp b/src/group_cmd.cpp
--- a/src/group_cmd.cpp
+++ b/src/group_cmd.cpp
@@ -170,7 +170,8 @@ static bool IsUniqueGroupName(const char
  */
 CommandCost CmdRenameGroup(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
-	if (!IsValidGroupID(p1) || StrEmpty(_cmd_text)) return CMD_ERROR;
+	if (!IsValidGroupID(p1)) return CMD_ERROR;
+	if (StrEmpty(_cmd_text) || strlen(_cmd_text) >= MAX_LENGTH_GROUP_NAME_BYTES) return CMD_ERROR;
 
 	Group *g = GetGroup(p1);
 	if (g->owner != _current_player) return CMD_ERROR;
diff --git a/src/players.cpp b/src/players.cpp
--- a/src/players.cpp
+++ b/src/players.cpp
@@ -366,8 +366,7 @@ verify_name:;
 		}
 
 		GetString(buffer, str, lastof(buffer));
-		if (strlen(buffer) >= 32 || GetStringBoundingBox(buffer).width >= 150)
-			goto bad_town_name;
+		if (strlen(buffer) >= MAX_LENGTH_COMPANY_NAME_BYTES) goto bad_town_name;
 
 set_name:;
 		p->name_1 = str;
diff --git a/src/signs.cpp b/src/signs.cpp
--- a/src/signs.cpp
+++ b/src/signs.cpp
@@ -133,6 +133,8 @@ CommandCost CmdRenameSign(TileIndex tile
 	/* If _cmd_text 0 means the new text for the sign is non-empty.
 	 * So rename the sign. If it is empty, it has no name, so delete it */
 	if (!StrEmpty(_cmd_text)) {
+		if (strlen(_cmd_text) >= MAX_LENGTH_SIGN_NAME_BYTES) return CMD_ERROR;
+
 		if (flags & DC_EXEC) {
 			Sign *si = GetSign(p1);
 
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2809,7 +2809,9 @@ static bool IsUniqueStationName(const ch
  */
 CommandCost CmdRenameStation(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
-	if (!IsValidStationID(p1) || StrEmpty(_cmd_text)) return CMD_ERROR;
+	if (!IsValidStationID(p1))
+	if (StrEmpty(_cmd_text) || strlen(_cmd_text) >= MAX_LENGTH_STATION_NAME_BYTES) return CMD_ERROR;
+
 	Station *st = GetStation(p1);
 
 	if (!CheckOwnership(st->owner)) return CMD_ERROR;
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1394,7 +1394,7 @@ restart:
 		}
 
 		/* Check size and width */
-		if (strlen(buf1) >= 31 || GetStringBoundingBox(buf1).width > 130) continue;
+		if (strlen(buf1) >= MAX_LENGTH_TOWN_NAME_BYTES || GetStringBoundingBox(buf1).width > MAX_LENGTH_TOWN_NAME_PIXELS) continue;
 
 		FOR_ALL_TOWNS(t2) {
 			/* We can't just compare the numbers since
@@ -2093,7 +2093,8 @@ static bool IsUniqueTownName(const char 
  */
 CommandCost CmdRenameTown(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
-	if (!IsValidTownID(p1) || StrEmpty(_cmd_text)) return CMD_ERROR;
+	if (!IsValidTownID(p1)) return CMD_ERROR;
+	if (StrEmpty(_cmd_text) || strlen(_cmd_text) >= MAX_LENGTH_TOWN_NAME_BYTES) return CMD_ERROR;
 
 	if (!IsUniqueTownName(_cmd_text)) return_cmd_error(STR_NAME_MUST_BE_UNIQUE);
 
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -1502,7 +1502,8 @@ static bool IsUniqueVehicleName(const ch
  */
 CommandCost CmdNameVehicle(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
-	if (!IsValidVehicleID(p1) || StrEmpty(_cmd_text)) return CMD_ERROR;
+	if (!IsValidVehicleID(p1)) return CMD_ERROR;
+	if (StrEmpty(_cmd_text) || strlen(_cmd_text) >= MAX_LENGTH_VEHICLE_NAME_BYTES) return CMD_ERROR;
 
 	Vehicle *v = GetVehicle(p1);
 
diff --git a/src/waypoint.cpp b/src/waypoint.cpp
--- a/src/waypoint.cpp
+++ b/src/waypoint.cpp
@@ -389,6 +389,7 @@ CommandCost CmdRenameWaypoint(TileIndex 
 	if (!CheckTileOwnership(wp->xy)) return CMD_ERROR;
 
 	if (!StrEmpty(_cmd_text)) {
+		if (strlen(_cmd_text) >= MAX_LENGTH_WAYPOINT_NAME_BYTES) return CMD_ERROR;
 		if (!IsUniqueWaypointName(_cmd_text)) return_cmd_error(STR_NAME_MUST_BE_UNIQUE);
 
 		if (flags & DC_EXEC) {