diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index c65a55ede4e..e0ebd248a5a 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -38,8 +38,12 @@ import 'inferrer/powersets/powersets.dart' show PowersetStrategy;
 import 'inferrer/typemasks/masks.dart' show TypeMaskStrategy;
 import 'inferrer/types.dart'
     show GlobalTypeInferenceResults, GlobalTypeInferenceTask;
+import 'inferrer_experimental/trivial.dart' as experimentalInferrer
+    show TrivialAbstractValueStrategy;
 import 'inferrer_experimental/types.dart' as experimentalInferrer
     show GlobalTypeInferenceTask;
+import 'inferrer_experimental/typemasks/masks.dart' as experimentalInferrer
+    show TypeMaskStrategy;
 import 'inferrer/wrapped.dart' show WrappedAbstractValueStrategy;
 import 'ir/modular.dart';
 import 'js_backend/backend.dart' show CodegenInputs;
@@ -158,9 +162,13 @@ class Compiler
     options.deriveOptions();
     options.validate();
 
-    abstractValueStrategy = options.useTrivialAbstractValueDomain
-        ? const TrivialAbstractValueStrategy()
-        : const TypeMaskStrategy();
+    abstractValueStrategy = options.experimentalInferrer
+        ? (options.useTrivialAbstractValueDomain
+            ? const experimentalInferrer.TrivialAbstractValueStrategy()
+            : const experimentalInferrer.TypeMaskStrategy())
+        : (options.useTrivialAbstractValueDomain
+            ? const TrivialAbstractValueStrategy()
+            : const TypeMaskStrategy());
     if (options.experimentalWrapped || options.testMode) {
       abstractValueStrategy =
           WrappedAbstractValueStrategy(abstractValueStrategy);
diff --git a/pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart b/pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart
index 816833cc33d..fd9f34ac300 100644
--- a/pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart
+++ b/pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart
@@ -271,9 +271,9 @@ abstract class TypeMask implements AbstractValue {
 
   /// If [mask] is forwarding, returns the first non-forwarding [TypeMask] in
   /// [mask]'s forwarding chain.
-  static TypeMask nonForwardingMask(mask) {
-    while (mask.isForwarding) {
-      mask = mask.forwardTo;
+  static TypeMask nonForwardingMask(TypeMask mask) {
+    while (mask is ForwardingTypeMask) {
+      mask = (mask as ForwardingTypeMask).forwardTo;
     }
     return mask;
   }
diff --git a/pkg/compiler/lib/src/inferrer_experimental/typemasks/type_mask.dart b/pkg/compiler/lib/src/inferrer_experimental/typemasks/type_mask.dart
index 816833cc33d..fd9f34ac300 100644
--- a/pkg/compiler/lib/src/inferrer_experimental/typemasks/type_mask.dart
+++ b/pkg/compiler/lib/src/inferrer_experimental/typemasks/type_mask.dart
@@ -271,9 +271,9 @@ abstract class TypeMask implements AbstractValue {
 
   /// If [mask] is forwarding, returns the first non-forwarding [TypeMask] in
   /// [mask]'s forwarding chain.
-  static TypeMask nonForwardingMask(mask) {
-    while (mask.isForwarding) {
-      mask = mask.forwardTo;
+  static TypeMask nonForwardingMask(TypeMask mask) {
+    while (mask is ForwardingTypeMask) {
+      mask = (mask as ForwardingTypeMask).forwardTo;
     }
     return mask;
   }
diff --git a/pkg/compiler/test/analyses/dart2js_allowed.json b/pkg/compiler/test/analyses/dart2js_allowed.json
index d8ca5912bc4..4cb50767a11 100644
--- a/pkg/compiler/test/analyses/dart2js_allowed.json
+++ b/pkg/compiler/test/analyses/dart2js_allowed.json
@@ -25,10 +25,6 @@
     "Dynamic access of 'memberContext'.": 1,
     "Dynamic access of 'name'.": 1
   },
-  "pkg/compiler/lib/src/inferrer/typemasks/type_mask.dart": {
-    "Dynamic access of 'forwardTo'.": 1,
-    "Dynamic access of 'isForwarding'.": 1
-  },
   "pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart": {
     "Dynamic invocation of '[]='.": 1,
     "Dynamic invocation of 'add'.": 1