diff --git a/spine-lua/Bone.lua b/spine-lua/Bone.lua
index ee1362a9a..cdf14aaa7 100644
--- a/spine-lua/Bone.lua
+++ b/spine-lua/Bone.lua
@@ -42,8 +42,16 @@ function Bone.new (data, parent)
 			self.worldScaleY = parent.worldScaleY * self.scaleY
 			self.worldRotation = parent.worldRotation + self.rotation
 		else
-			self.worldX = flipX ? -self.x : self.x
-			self.worldY = flipY ? -self.y : self.y
+			if flipX then
+				self.worldX = -self.x
+			else
+				self.worldX = self.x
+			end
+			if flipY then
+				self.worldY = -self.y
+			else
+				self.worldY = self.y
+			end
 			self.worldScaleX = self.scaleX
 			self.worldScaleY = self.scaleY
 			self.worldRotation = self.rotation