diff --git a/frontend/src/Main.elm b/frontend/src/Main.elm
index d66ae73..d367ba0 100644
--- a/frontend/src/Main.elm
+++ b/frontend/src/Main.elm
@@ -246,12 +246,10 @@ updateModel msg model =
 
                 _ -> model
         TimeScale factor ->
-            let fudge = factor
-                len = model.duration - fudge
-            in { model |
-                     startTime = model.startTime + fudge / 2
-               ,     duration = len
-               }
+            { model |
+                  startTime = model.startTime + factor / 2
+            ,     duration = model.duration - factor
+            }
 
         Loaded result ->
             case result of