diff --git a/examples/virtual-dom-wip/platform/Html/Internal/Client.roc b/examples/virtual-dom-wip/platform/Html/Internal/Client.roc
index 5f9dd16948..acef1dfc4d 100644
--- a/examples/virtual-dom-wip/platform/Html/Internal/Client.roc
+++ b/examples/virtual-dom-wip/platform/Html/Internal/Client.roc
@@ -723,7 +723,7 @@ expect
 
 # diff
 expect
-    State : { answer : Nat }
+    State : { answer : U64 }
 
     diffStateBefore : DiffState State
     diffStateBefore = {
@@ -778,7 +778,7 @@ expect
 
 # initClientAppHelp
 expect
-    State : { answer : Nat }
+    State : { answer : U64 }
 
     init = \result ->
         when result is
diff --git a/examples/virtual-dom-wip/platform/Html/Internal/Shared.roc b/examples/virtual-dom-wip/platform/Html/Internal/Shared.roc
index 757ebfedc7..cacba350a9 100644
--- a/examples/virtual-dom-wip/platform/Html/Internal/Shared.roc
+++ b/examples/virtual-dom-wip/platform/Html/Internal/Shared.roc
@@ -43,7 +43,7 @@ Attribute state : [
 
 CyclicStructureAccessor : [
     ObjectField Str CyclicStructureAccessor,
-    ArrayIndex Nat CyclicStructureAccessor,
+    ArrayIndex U64 CyclicStructureAccessor,
     SerializableValue,
 ]