diff --git a/Lib/turtle.py b/Lib/turtle.py
index 08c5b47..7d94720 100644
--- a/Lib/turtle.py
+++ b/Lib/turtle.py
@@ -1645,7 +1645,7 @@ def back(self, distance):
         Argument:
         distance -- a number
 
-        Move the turtle backward by distance ,opposite to the direction the
+        Move the turtle backward by distance, opposite to the direction the
         turtle is headed. Do not change the turtle's heading.
 
         Example (for a Turtle instance named turtle):