diff --git a/gamedata/objects/ingame/tileset.py b/gamedata/objects/ingame/tileset.py
index edc17c9..184330f 100644
--- a/gamedata/objects/ingame/tileset.py
+++ b/gamedata/objects/ingame/tileset.py
@@ -23,6 +23,17 @@ class TilesetRenderer(BaseObject):
 
         self.bgoffset = self.layers[0]["surface"].get_height()/2-self.game.globals["camerah"]
 
+        # Prescale backgrounds
+        self.sep = self.game.pygame.transform.scale(self.game.sprite_lib["backgroundseparator.png"],[self.game.globals["cameraw"],self.game.globals["camerah"]])
+        self.scaledbgs = []
+        wratio = self.game.globals["cameraw"]/self.bgs[0]["sprite"].get_width()
+        hratio = self.game.globals["camerah"]/self.bgs[0]["sprite"].get_height()
+        for bg in self.bgs:
+            width, height = round(bg["sprite"].get_width()*wratio),round(bg["sprite"].get_height()*hratio)
+            sprite = self.game.pygame.transform.scale(bg["sprite"],(width,height))
+            self.scaledbgs.append(sprite)
+
+
     def step(self):
         # Spawning ennemies
         while len(self.queue)>0:
@@ -31,24 +42,21 @@ class TilesetRenderer(BaseObject):
             self.game.gameloop.summon(e)
 
     def draw(self):
-        wratio = self.game.globals["cameraw"]/self.bgs[0]["sprite"].get_width()
-        hratio = self.game.globals["camerah"]/self.bgs[0]["sprite"].get_height()
         lastoffset = 0
-        for i,bg in enumerate(self.bgs):
+        for i,bg in enumerate(self.scaledbgs):
             ratio = 1-(len(self.bgs)-i)/len(self.bgs)
-            width, height = round(bg["sprite"].get_width()*wratio),round(bg["sprite"].get_height()*hratio)
-            sprite = self.game.pygame.transform.scale(bg["sprite"],(width,height))
+            width = bg.get_width()
+            height = bg.get_height()
             nbs = self.game.globals["cameraw"]/width
             lastoffset = self.rect[1]+(self.bgoffset-self.game.globals["cameray"])*ratio
             for i in range(round(nbs+0.5)):
-                self.game.window.blit(sprite,[(-self.game.globals["camerax"]*ratio)%width+(i-1)*width,lastoffset])
+                self.game.window.blit(bg,[(-self.game.globals["camerax"]*ratio)%width+(i-1)*width,lastoffset])
         # Draw filler
         if self.level["filler"]:
             filleroffset = lastoffset+height
             self.game.window.blit(self.level["filler"],[0,filleroffset])
         # Separator
-        sep = self.game.pygame.transform.scale(self.game.sprite_lib["backgroundseparator.png"],[self.game.globals["cameraw"],self.game.globals["camerah"]])
-        self.game.window.blit(sep,[0,0])
+        self.game.window.blit(self.sep,[0,0])
         # Layers
         for layer in self.layers:
             self.game.window.blit(layer["surface"],(layer["offsets"][0]-self.game.globals["camerax"],layer["offsets"][1]-self.game.globals["cameray"]))