diff --git a/lib/xmet/skew_t.py b/lib/xmet/skew_t.py
index 58e0f48..db74adf 100644
--- a/lib/xmet/skew_t.py
+++ b/lib/xmet/skew_t.py
@@ -169,11 +169,11 @@ class SkewTGraph():
         cr.stroke()
 
     def draw_sounding(self,
-                     cr: cairo.Context,
-                     x: float,
-                     y: float,
-                     sounding: Sounding,
-                     fn: Callable):
+                      cr: cairo.Context,
+                      x: float,
+                      y: float,
+                      sounding: Sounding,
+                      fn: Callable):
         cr.save()
 
         first = True