diff --git a/src/Wave.elm b/src/Wave.elm
index 9219cc3..ed53585 100644
--- a/src/Wave.elm
+++ b/src/Wave.elm
@@ -223,8 +223,7 @@ propagateInDirection source sourceCell direction ( Wave wave, todo ) =
                                 }
                                 wave.entropy
                     }
-                , -- TODO: add this as a target for propagation if it's not already in this list -
-                  if Set.isEmpty reduced then
+                , if Set.isEmpty reduced then
                     -- we're blocked and should stop immediately
                     []