diff --git a/binaries/data/mods/public/maps/random/rmgen/map.js b/binaries/data/mods/public/maps/random/rmgen/map.js
index e856fbfac8..ed7cb8c558 100644
--- a/binaries/data/mods/public/maps/random/rmgen/map.js
+++ b/binaries/data/mods/public/maps/random/rmgen/map.js
@@ -300,7 +300,7 @@ Map.prototype.getMapData = function()
 	// Convert 2D heightmap array to flat array
 	//	Flat because it's easier to handle by the engine
 	var mapSize = size+1;
-	var height16 = new Array(mapSize*mapSize);		// uint16
+	var height16 = new Uint16Array(mapSize*mapSize);		// uint16
 	for (var x = 0; x < mapSize; x++)
 	{
 		for (var z = 0; z < mapSize; z++)
@@ -332,16 +332,18 @@ Map.prototype.getMapData = function()
 	data["textureNames"] = textureNames;
 	
 	//  Convert 2D tile data to flat array
-	var tiles = new Array(size*size);
+	var tileIndex = new Uint16Array(size*size);
+	var tilePriority = new Uint16Array(size*size);
 	for (var x = 0; x < size; x++)
 	{
 		for (var z = 0; z < size; z++)
 		{
 			// TODO: For now just use the texture's index as priority, might want to do this another way
-			tiles[z*size + x] = { "idx": this.texture[x][z], "priority": this.texture[x][z] };
+			tileIndex[z*size + x] = this.texture[x][z];
+			tilePriority[z*size + x] = this.texture[x][z];
 		}
 	}
-	data["tileData"] = tiles;
+	data["tileData"] = {"index": tileIndex, "priority": tilePriority};
 	
 	return data;
 };
diff --git a/source/graphics/MapReader.cpp b/source/graphics/MapReader.cpp
index 0e94d73674..93ac740df6 100644
--- a/source/graphics/MapReader.cpp
+++ b/source/graphics/MapReader.cpp
@@ -1140,22 +1140,22 @@ int CMapReader::ParseTerrain()
 
 	// parse terrain from map data
 	//	an error here should stop the loading process
-#define GET_TERRAIN_PROPERTY(prop, out)\
-	if (!pSimulation2->GetScriptInterface().GetProperty(m_MapData.get(), #prop, out))\
+#define GET_TERRAIN_PROPERTY(val, prop, out)\
+	if (!pSimulation2->GetScriptInterface().GetProperty(val, #prop, out))\
 		{	LOGERROR(L"CMapReader::ParseTerrain() failed to get '%hs' property", #prop);\
 			throw PSERROR_Game_World_MapLoadFailed("Error parsing terrain data.\nCheck application log for details"); }
 
 	u32 size;
-	GET_TERRAIN_PROPERTY(size, size)
+	GET_TERRAIN_PROPERTY(m_MapData.get(), size, size)
 
 	m_PatchesPerSide = size / PATCH_SIZE;
 
 	// flat heightmap of u16 data
-	GET_TERRAIN_PROPERTY(height, m_Heightmap)
+	GET_TERRAIN_PROPERTY(m_MapData.get(), height, m_Heightmap)
 
 	// load textures
 	std::vector<std::string> textureNames;
-	GET_TERRAIN_PROPERTY(textureNames, textureNames)
+	GET_TERRAIN_PROPERTY(m_MapData.get(), textureNames, textureNames)
 	num_terrain_tex = textureNames.size();
 
 	while (cur_terrain_tex < num_terrain_tex)
@@ -1170,11 +1170,16 @@ int CMapReader::ParseTerrain()
 	// build tile data
 	m_Tiles.resize(SQR(size));
 
-	// flat array of tile descriptors
-	std::vector<CMapIO::STileDesc> tileData;
-	GET_TERRAIN_PROPERTY(tileData, tileData)
+	CScriptValRooted tileData;
+	GET_TERRAIN_PROPERTY(m_MapData.get(), tileData, tileData)
 
-	ENSURE(SQR(size) == tileData.size());
+	// parse tile data object into flat arrays
+	std::vector<u16> tileIndex;
+	std::vector<u16> tilePriority;
+	GET_TERRAIN_PROPERTY(tileData.get(), index, tileIndex);
+	GET_TERRAIN_PROPERTY(tileData.get(), priority, tilePriority);
+
+	ENSURE(SQR(size) == tileIndex.size() && SQR(size) == tilePriority.size());
 
 	// reorder by patches and store
 	for (size_t x = 0; x < size; ++x)
@@ -1186,7 +1191,11 @@ int CMapReader::ParseTerrain()
 			size_t patchY = y / PATCH_SIZE;
 			size_t offY = y % PATCH_SIZE;
 			
-			m_Tiles[(patchY * m_PatchesPerSide + patchX) * SQR(PATCH_SIZE) + (offY * PATCH_SIZE + offX)] = tileData[y*size + x];
+			STileDesc tile;
+			tile.m_Tex1Index = tileIndex[y*size + x];
+			tile.m_Priority = tilePriority[y*size + x];
+
+			m_Tiles[(patchY * m_PatchesPerSide + patchX) * SQR(PATCH_SIZE) + (offY * PATCH_SIZE + offX)] = tile;
 		}
 	}
 
diff --git a/source/scriptinterface/ScriptConversions.cpp b/source/scriptinterface/ScriptConversions.cpp
index 7ff1a4e440..9b1d2c9e0c 100644
--- a/source/scriptinterface/ScriptConversions.cpp
+++ b/source/scriptinterface/ScriptConversions.cpp
@@ -20,7 +20,6 @@
 #include "ScriptInterface.h"
 
 #include "graphics/Entity.h"
-#include "graphics/MapIO.h"
 #include "ps/utf16string.h"
 #include "ps/CLogger.h"
 #include "ps/CStr.h"
@@ -167,21 +166,6 @@ template<> bool ScriptInterface::FromJSVal<Entity>(JSContext* cx, jsval v, Entit
 	return true;
 }
 
-template<> bool ScriptInterface::FromJSVal<CMapIO::STileDesc>(JSContext* cx, jsval v, CMapIO::STileDesc& out)
-{
-	JSObject* obj;
-	if (!JS_ValueToObject(cx, v, &obj) || obj == NULL)
-		FAIL("Argument must be an object");
-
-	jsval texIdx, priority;
-	if (!JS_GetProperty(cx, obj, "idx", &texIdx) || !FromJSVal(cx, texIdx, out.m_Tex1Index))
-		FAIL("Failed to read CMapIO::STileDesc.m_Tex1Index property");
-	if (!JS_GetProperty(cx, obj, "priority", &priority) || !FromJSVal(cx, priority, out.m_Priority))
-		FAIL("Failed to read CMapIO::STileDesc.m_Priority property");
-	
-	return true;
-}
-
 ////////////////////////////////////////////////////////////////
 // Primitive types:
 
@@ -348,8 +332,3 @@ template<> bool ScriptInterface::FromJSVal<std::vector<Entity> >(JSContext* cx,
 {
 	return FromJSVal_vector(cx, v, out);
 }
-
-template<> bool ScriptInterface::FromJSVal<std::vector<CMapIO::STileDesc> >(JSContext* cx, jsval v, std::vector<CMapIO::STileDesc>& out)
-{
-	return FromJSVal_vector(cx, v, out);
-}