diff --git a/src/mutation/__tests__/mutation.js b/src/mutation/__tests__/mutation.js
index 20beacc..55d42b4 100644
--- a/src/mutation/__tests__/mutation.js
+++ b/src/mutation/__tests__/mutation.js
@@ -57,12 +57,24 @@ var simplePromiseMutation = mutationWithClientMutationId({
   mutateAndGetPayload: () => Promise.resolve({result: 1})
 });
 
+var simpleRootValueMutation = mutationWithClientMutationId({
+  name: 'SimpleRootValueMutation',
+  inputFields: {},
+  outputFields: {
+    result: {
+      type: GraphQLInt
+    }
+  },
+  mutateAndGetPayload: (params, context, {rootValue}) => (rootValue)
+});
+
 var mutation = new GraphQLObjectType({
   name: 'Mutation',
   fields: {
     simpleMutation: simpleMutation,
     simpleMutationWithThunkFields: simpleMutationWithThunkFields,
-    simplePromiseMutation: simplePromiseMutation
+    simplePromiseMutation: simplePromiseMutation,
+    simpleRootValueMutation: simpleRootValueMutation
   }
 });
 
@@ -145,6 +157,26 @@ describe('mutationWithClientMutationId()', () => {
     return expect(graphql(schema, query)).to.become(expected);
   });
 
+  it('can access rootValue', () => {
+    var query = `
+      mutation M {
+        simpleRootValueMutation(input: {clientMutationId: "abc"}) {
+          result
+          clientMutationId
+        }
+      }
+    `;
+    var expected = {
+      data: {
+        simpleRootValueMutation: {
+          result: 1,
+          clientMutationId: 'abc'
+        }
+      }
+    };
+    return expect(graphql(schema, query, {result: 1})).to.become(expected);
+  });
+
   describe('introspection', () => {
     it('contains correct input', () => {
       var query = `{
@@ -325,6 +357,26 @@ describe('mutationWithClientMutationId()', () => {
                   kind: 'OBJECT',
                 }
               },
+              {
+                name: 'simpleRootValueMutation',
+                args: [
+                  {
+                    name: 'input',
+                    type: {
+                      name: null,
+                      kind: 'NON_NULL',
+                      ofType: {
+                        name: 'SimpleRootValueMutationInput',
+                        kind: 'INPUT_OBJECT'
+                      }
+                    },
+                  }
+                ],
+                type: {
+                  name: 'SimpleRootValueMutationPayload',
+                  kind: 'OBJECT',
+                }
+              },
             ]
           }
         }
diff --git a/src/mutation/mutation.js b/src/mutation/mutation.js
index 5fae43e..c5478d3 100644
--- a/src/mutation/mutation.js
+++ b/src/mutation/mutation.js
@@ -22,8 +22,9 @@ import type {
   GraphQLResolveInfo
 } from 'graphql';
 
-type mutationFn = (object: Object, info: GraphQLResolveInfo) => Object |
-                  (object: Object, info: GraphQLResolveInfo) => Promise<Object>;
+type mutationFn =
+  (object: Object, ctx: Object, info: GraphQLResolveInfo) => Object |
+  (object: Object, ctx: Object, info: GraphQLResolveInfo) => Promise<Object>;
 
 function resolveMaybeThunk<T>(thingOrThunk: T | () => T): T {
   return typeof thingOrThunk === 'function' ? thingOrThunk() : thingOrThunk;