diff --git a/adafruit_display_shapes/multisparkline.py b/adafruit_display_shapes/multisparkline.py
index acc1bee..0d01b8b 100644
--- a/adafruit_display_shapes/multisparkline.py
+++ b/adafruit_display_shapes/multisparkline.py
@@ -172,10 +172,8 @@ def add_values(self, values: List[float], update: bool = True) -> None:
         call the update()-method
         """
 
-        lines_to_update = []
         for i, value in enumerate(values):
             if value is not None:
-                lines_to_update.append(i)
                 top = self.y_tops[i]
                 bottom = self.y_bottoms[i]
                 if (
@@ -197,8 +195,8 @@ def add_values(self, values: List[float], update: bool = True) -> None:
                 self.y_tops[i] = top
                 self.y_bottoms[i] = bottom
 
-        if update and lines_to_update:
-            self.update_line(lines_to_update)
+                if update:
+                    self.update_line(i)
 
     def _add_point(
         self,