diff --git a/.travis.yml b/.travis.yml
index 2b8d5af..82091ab 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,33 +1,28 @@
 language: dart
 
 dart:
-- preview/raw/2.10.0-0.2-dev
+- dev
 
 jobs:
   include:
     - stage: analyze_and_format
       name: "Analyze lib/"
-      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartanalyzer --fatal-warnings --fatal-infos lib/
     - stage: analyze_and_format
       name: "Analyze test/"
-      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartanalyzer --enable-experiment=non-nullable --fatal-warnings --fatal-infos test/
     - stage: analyze_and_format
       name: "Format"
-      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartfmt -n --set-exit-if-changed .
     - stage: test
       name: "Vm Tests"
-      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: pub run --enable-experiment=non-nullable test -p vm 
     - stage: test
       name: "Web Tests"
-      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: pub run --enable-experiment=non-nullable test -p chrome
 
diff --git a/test/wrapper_test.dart b/test/wrapper_test.dart
index 2612867..f31499b 100644
--- a/test/wrapper_test.dart
+++ b/test/wrapper_test.dart
@@ -186,7 +186,7 @@
     (expect..firstWhere(boolFunc, orElse: func0))
         .equals
         .firstWhere(boolFunc, orElse: func0);
-    (expect..fold(null, foldFunc)).equals.fold(null, foldFunc);
+    (expect..fold(42, foldFunc)).equals.fold(42, foldFunc);
     (expect..forEach(boolFunc)).equals.forEach(boolFunc);
     (expect..isEmpty).equals.isEmpty;
     (expect..isNotEmpty).equals.isNotEmpty;