diff --git a/kivy/data/style.kv b/kivy/data/style.kv
index b1d4c35ca..1b09908d4 100644
--- a/kivy/data/style.kv
+++ b/kivy/data/style.kv
@@ -27,7 +27,7 @@
             pos: int(self.center_x - self.texture_size[0] / 2.), int(self.center_y - self.texture_size[1] / 2.)
 
 <BubbleContent>
-	rows: 1
+    rows: 1
     canvas:
         Color:
             rgba: self.parent.background_color if self.parent else (1, 1, 1, 1)