diff --git a/CHANGELOG.md b/CHANGELOG.md
index feb1001..cb13d7b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.0.2
+
+* Fix all strong-mode warnings.
+
 ## 2.0.1
 
 * Fix a race condition in which a `StateError` could be top-leveled if
diff --git a/lib/src/client.dart b/lib/src/client.dart
index 5df21e4..82baa6a 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -121,7 +121,7 @@
           'parameters, was "$parameters".');
     }
 
-    var message = {
+    var message = <String, dynamic>{
       "jsonrpc": "2.0",
       "method": method
     };
diff --git a/lib/src/parameters.dart b/lib/src/parameters.dart
index 91ad1b5..c6c653b 100644
--- a/lib/src/parameters.dart
+++ b/lib/src/parameters.dart
@@ -26,9 +26,10 @@
   ///
   /// If this is accessed for a [Parameter] that was not passed, the request
   /// will be automatically rejected. To avoid this, use [Parameter.valueOr].
-  final value;
+  get value => _value;
+  final _value;
 
-  Parameters(this.method, this.value);
+  Parameters(this.method, this._value);
 
   /// Returns a single parameter.
   ///
@@ -141,15 +142,16 @@
       }
 
       var path = computePath(params._parent);
-      return params._key is int ?
-          "$path[${params._key}]" : "$path.${quoteKey(params._key)}";
+      return params._key is int
+          ? "$path[${params._key}]"
+          : "$path.${quoteKey(params._key)}";
     }
 
     return computePath(this);
   }
 
   /// Whether this parameter exists.
-  final exists = true;
+  bool get exists => true;
 
   Parameter._(String method, value, this._parent, this._key)
       : super(method, value);
@@ -307,7 +309,7 @@
         'missing required parameter $_path.');
   }
 
-  final exists = false;
+  bool get exists => false;
 
   _MissingParameter(String method, Parameters parent, key)
       : super._(method, null, parent, key);
diff --git a/pubspec.yaml b/pubspec.yaml
index 8cb0dc8..01cb528 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: json_rpc_2
-version: 2.0.1
+version: 2.0.2
 author: Dart Team <misc@dartlang.org>
 description: An implementation of the JSON-RPC 2.0 spec.
 homepage: http://github.com/dart-lang/json_rpc_2