diff --git a/src/cheat_gui.cpp b/src/cheat_gui.cpp
--- a/src/cheat_gui.cpp
+++ b/src/cheat_gui.cpp
@@ -125,7 +125,8 @@ static int32 ClickChangeDateCheat(int32 
  * @return New value (or unchanged old value) of the maximum
  *         allowed heightlevel value.
  */
-static int32 ClickChangeMaxHlCheat(int32 p1, int32 p2) {
+static int32 ClickChangeMaxHlCheat(int32 p1, int32 p2)
+{
 	p1 = Clamp(p1, MIN_MAX_HEIGHTLEVEL, MAX_MAX_HEIGHTLEVEL);
 
 	/* Check if at least one mountain on the map is higher than the new value.
diff --git a/src/settings.cpp b/src/settings.cpp
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1277,6 +1277,27 @@ static bool ChangeDynamicEngines(int32 p
 	return true;
 }
 
+static bool ChangeMaxHeightLevel(int32 p1)
+{
+	if (_game_mode == GM_NORMAL) return false;
+	if (_game_mode != GM_EDITOR) return true;
+
+	/* Check if at least one mountain on the map is higher than the new value.
+	 * If yes, disallow the change. */
+	for (TileIndex t = 0; t < MapSize(); t++) {
+		if ((int32)TileHeight(t) > p1) {
+			ShowErrorMessage(STR_CONFIG_SETTING_TOO_HIGH_MOUNTAIN, INVALID_STRING_ID, WL_ERROR);
+			/* Return old, unchanged value */
+			return false;
+		}
+	}
+
+	/* The smallmap uses an index from heightlevels to colours. Trigger rebuilding it. */
+	InvalidateWindowClassesData(WC_SMALLMAP, 2);
+
+	return true;
+}
+
 static bool StationCatchmentChanged(int32 p1)
 {
 	Station::RecomputeIndustriesNearForAll();
diff --git a/src/table/settings.ini b/src/table/settings.ini
--- a/src/table/settings.ini
+++ b/src/table/settings.ini
@@ -28,6 +28,7 @@ static bool TownFoundingChanged(int32 p1
 static bool DifficultyNoiseChange(int32 i);
 static bool MaxNoAIsChange(int32 i);
 static bool CheckRoadSide(int p1);
+static bool ChangeMaxHeightLevel(int32 p1);
 static bool CheckFreeformEdges(int32 p1);
 static bool ChangeDynamicEngines(int32 p1);
 static bool StationCatchmentChanged(int32 p1);
@@ -382,7 +383,7 @@ base     = GameSettings
 var      = construction.max_heightlevel
 type     = SLE_UINT8
 from     = 194
-guiflags = SGF_NEWGAME_ONLY | SGF_NO_NETWORK
+guiflags = SGF_NEWGAME_ONLY | SGF_SCENEDIT_TOO
 def      = DEF_MAX_HEIGHTLEVEL
 min      = MIN_MAX_HEIGHTLEVEL
 max      = MAX_MAX_HEIGHTLEVEL
@@ -390,6 +391,7 @@ interval = 1
 str      = STR_CONFIG_SETTING_MAX_HEIGHTLEVEL
 strhelp  = STR_CONFIG_SETTING_MAX_HEIGHTLEVEL_HELPTEXT
 strval   = STR_JUST_INT
+proc     = ChangeMaxHeightLevel
 cat      = SC_BASIC
 
 [SDT_BOOL]