diff --git a/desktop_version/src/FileSystemUtils.cpp b/desktop_version/src/FileSystemUtils.cpp
index a42d1137..4cbb6e50 100644
--- a/desktop_version/src/FileSystemUtils.cpp
+++ b/desktop_version/src/FileSystemUtils.cpp
@@ -165,6 +165,8 @@ void FILESYSTEM_mount(const char *fname)
 	}
 }
 
+bool FILESYSTEM_assetsmounted = false;
+
 void FILESYSTEM_mountassets(const char* path)
 {
 	const std::string _path(path);
@@ -182,6 +184,7 @@ void FILESYSTEM_mountassets(const char* path)
 		printf("Custom asset directory exists at %s\n", zippath.c_str());
 		FILESYSTEM_mount(zippath.c_str());
 		graphics.reloadresources();
+		FILESYSTEM_assetsmounted = true;
 	} else if (zip_path != "data.zip" && !endsWith(zip_path, "/data.zip") && endsWith(zip_path, ".zip")) {
 		printf("Custom asset directory is .zip at %s\n", zip_path.c_str());
 		PHYSFS_File* zip = PHYSFS_openRead(zip_path.c_str());
@@ -193,13 +196,16 @@ void FILESYSTEM_mountassets(const char* path)
 		} else {
 			graphics.assetdir = zip_path;
 		}
+		FILESYSTEM_assetsmounted = true;
 		graphics.reloadresources();
 	} else if (FILESYSTEM_directoryExists(dirpath.c_str())) {
 		printf("Custom asset directory exists at %s\n",dirpath.c_str());
 		FILESYSTEM_mount(dirpath.c_str());
 		graphics.reloadresources();
+		FILESYSTEM_assetsmounted = true;
 	} else {
 		printf("Custom asset directory does not exist\n");
+		FILESYSTEM_assetsmounted = false;
 	}
 }
 
@@ -216,6 +222,7 @@ void FILESYSTEM_unmountassets()
 	{
 		printf("Cannot unmount when no asset directory is mounted\n");
 	}
+	FILESYSTEM_assetsmounted = false;
 }
 
 void FILESYSTEM_loadFileToMemory(
diff --git a/desktop_version/src/FileSystemUtils.h b/desktop_version/src/FileSystemUtils.h
index e08a24cb..254383f4 100644
--- a/desktop_version/src/FileSystemUtils.h
+++ b/desktop_version/src/FileSystemUtils.h
@@ -15,6 +15,7 @@ char *FILESYSTEM_getUserLevelDirectory();
 
 bool FILESYSTEM_directoryExists(const char *fname);
 void FILESYSTEM_mount(const char *fname);
+extern bool FILESYSTEM_assetsmounted;
 void FILESYSTEM_mountassets(const char *path);
 void FILESYSTEM_unmountassets();
 
diff --git a/desktop_version/src/Graphics.cpp b/desktop_version/src/Graphics.cpp
index 70f87afc..b1eee6da 100644
--- a/desktop_version/src/Graphics.cpp
+++ b/desktop_version/src/Graphics.cpp
@@ -640,7 +640,7 @@ void Graphics::drawtile( int x, int y, int t )
     SDL_Rect rect = { Sint16(x), Sint16(y), tiles_rect.w, tiles_rect.h };
 
 #if !defined(NO_CUSTOM_LEVELS)
-    if (t >= 14 && t <= 17)
+    if (t >= 14 && t <= 17 && !FILESYSTEM_assetsmounted)
     {
         colourTransform thect = {ed.getonewaycol()};
         BlitSurfaceTinted(tiles[t], NULL, backBuffer, &rect, thect);
@@ -663,7 +663,7 @@ void Graphics::drawtile2( int x, int y, int t )
     SDL_Rect rect = { Sint16(x), Sint16(y), tiles_rect.w, tiles_rect.h };
 
 #if !defined(NO_CUSTOM_LEVELS)
-    if (t >= 14 && t <= 17)
+    if (t >= 14 && t <= 17 && !FILESYSTEM_assetsmounted)
     {
         colourTransform thect = {ed.getonewaycol()};
         BlitSurfaceTinted(tiles2[t], NULL, backBuffer, &rect, thect);
@@ -3119,7 +3119,7 @@ void Graphics::drawforetile(int x, int y, int t)
 	setRect(rect, x,y,tiles_rect.w, tiles_rect.h);
 
 #if !defined(NO_CUSTOM_LEVELS)
-	if (t >= 14 && t <= 17)
+	if (t >= 14 && t <= 17 && !FILESYSTEM_assetsmounted)
 	{
 		colourTransform thect = {ed.getonewaycol()};
 		BlitSurfaceTinted(tiles[t], NULL, foregroundBuffer, &rect, thect);
@@ -3142,7 +3142,7 @@ void Graphics::drawforetile2(int x, int y, int t)
 	setRect(rect, x,y,tiles_rect.w, tiles_rect.h);
 
 #if !defined(NO_CUSTOM_LEVELS)
-	if (t >= 14 && t <= 17)
+	if (t >= 14 && t <= 17 && !FILESYSTEM_assetsmounted)
 	{
 		colourTransform thect = {ed.getonewaycol()};
 		BlitSurfaceTinted(tiles2[t], NULL, foregroundBuffer, &rect, thect);