diff --git a/example/DeltaBlue.dart b/example/DeltaBlue.dart
index 96c2af3..3eb23b4 100644
--- a/example/DeltaBlue.dart
+++ b/example/DeltaBlue.dart
@@ -448,7 +448,7 @@
 
   /// Removes all traces of c from this variable.
   void removeConstraint(Constraint c) {
-    constraints = constraints.filter((e) => c != e);
+    constraints = constraints.where((e) => c != e).toList();
     if (determinedBy == c) determinedBy = null;
   }
 }
diff --git a/example/Richards.dart b/example/Richards.dart
index e0a8364..a5720b6 100644
--- a/example/Richards.dart
+++ b/example/Richards.dart
@@ -120,7 +120,7 @@
   int currentId;
   TaskControlBlock list;
   List<TaskControlBlock> blocks =
-    new List<TaskControlBlock>(Richards.NUMBER_OF_IDS);
+    new List<TaskControlBlock>.fixedLength(Richards.NUMBER_OF_IDS);
 
   /// Add an idle task to this scheduler.
   void addIdleTask(int id, int priority, Packet queue, int count) {
@@ -461,7 +461,7 @@
   int kind;    // The type of this packet.
   int a1 = 0;
 
-  List<int> a2 = new List(Richards.DATA_SIZE);
+  List<int> a2 = new List.fixedLength(Richards.DATA_SIZE);
 
   Packet(this.link, this.id, this.kind);