diff --git a/lib/async_helpers.dart b/lib/async_helpers.dart
index b0d7609..8b1d311 100644
--- a/lib/async_helpers.dart
+++ b/lib/async_helpers.dart
@@ -67,7 +67,7 @@
         ..add('\n');
 
       var mismatchDescription = new StringDescription();
-      matcher.describeMismatch(value, mismatchDescription, matchState);
+      matcher.describeMismatch(value, mismatchDescription, matchState, true);
       if (mismatchDescription.length > 0) {
         desc.add('   Which: ${mismatchDescription}\n');
       }
diff --git a/pubspec.yaml b/pubspec.yaml
index 903413d..fd8dba8 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: webdriver
-version: 0.10.0-pre.6
+version: 0.10.0-pre.7
 author: Marc Fisher II <fisherii@google.com>
 description: >
   Provides WebDriver bindings for Dart. These use the WebDriver JSON interface,