diff --git a/Beam.Models/ResourceDefinition.cs b/Beam.Models/ResourceDefinition.cs
index ff74b31..8820e02 100644
--- a/Beam.Models/ResourceDefinition.cs
+++ b/Beam.Models/ResourceDefinition.cs
@@ -19,8 +19,8 @@ public class ResourceDefinition {
     }
 
     public class UrlLocation {
-        public ILinkBuilder Segments { get; init; }
-        public List<ImmutableState> States { get; init; }
-        public IStateChangerFactory StateChanger { get; init; }
+        public required ILinkBuilder Segments { get; init; }
+        public required List<ImmutableState> States { get; init; }
+        public required IStateChangerFactory StateChanger { get; init; }
     }
 }
\ No newline at end of file
diff --git a/Beam/OrderedLinkGenerator.cs b/Beam/OrderedLinkGenerator.cs
index 2fd6708..92b9305 100644
--- a/Beam/OrderedLinkGenerator.cs
+++ b/Beam/OrderedLinkGenerator.cs
@@ -15,14 +15,14 @@ namespace Beam {
 
     public class OrderedLinkGenerator : IEnumerator<string?> {
         public ILinkBuilder Builder { get; set; }
-        public NumberedStateChanger Behaviour { get; }
+        public IStateChangeBehaviour Behaviour { get; }
         
         private IState? EndState;
         private IState InitialState;
 
-        public OrderedLinkGenerator(ILinkBuilder builder, NumberedStateChanger behaviour, params string[] initialState) 
+        public OrderedLinkGenerator(ILinkBuilder builder, IStateChangeBehaviour behaviour, params string[] initialState) 
             : this(builder, behaviour, new State(initialState)) { }
-        public OrderedLinkGenerator(ILinkBuilder builder, NumberedStateChanger behaviour, IState initialState, IState? endState = null) {
+        public OrderedLinkGenerator(ILinkBuilder builder, IStateChangeBehaviour behaviour, IState initialState, IState? endState = null) {
             Builder = builder;
             Behaviour = behaviour;
             InitialState = initialState.Copy();