diff --git a/apitest.go b/apitest.go
index 80d32a4..096352e 100644
--- a/apitest.go
+++ b/apitest.go
@@ -137,6 +137,12 @@ func (a *APITest) Handler(handler http.Handler) *APITest {
 	return a
 }
 
+// HandlerFunc defines the http handler that is invoked when the test is run
+func (a *APITest) HandlerFunc(handlerFunc http.HandlerFunc) *APITest {
+	a.handler = handlerFunc
+	return a
+}
+
 // Mocks is a builder method for setting the mocks
 func (a *APITest) Mocks(mocks ...*Mock) *APITest {
 	var m []*Mock
@@ -689,10 +695,7 @@ func (r *Response) runTest() *http.Response {
 	a.assertResponse(res)
 	a.assertHeaders(res)
 	a.assertCookies(res)
-	err := a.assertFunc(res, req)
-	if err != nil {
-		a.t.Fatal(err.Error())
-	}
+	a.assertFunc(res, req)
 
 	return copyHttpResponse(res)
 }
@@ -705,16 +708,15 @@ func (a *APITest) assertMocks() {
 	}
 }
 
-func (a *APITest) assertFunc(res *http.Response, req *http.Request) error {
+func (a *APITest) assertFunc(res *http.Response, req *http.Request) {
 	if len(a.response.assert) > 0 {
 		for _, assertFn := range a.response.assert {
 			err := assertFn(copyHttpResponse(res), copyHttpRequest(req))
 			if err != nil {
-				return err
+				a.verifier.Equal(a.t, nil, err)
 			}
 		}
 	}
-	return nil
 }
 
 func (a *APITest) doRequest() (*http.Response, *http.Request) {
diff --git a/apitest_test.go b/apitest_test.go
index 476f95d..3875662 100644
--- a/apitest_test.go
+++ b/apitest_test.go
@@ -2,8 +2,6 @@ package apitest_test
 
 import (
 	"fmt"
-	"github.com/steinfletcher/apitest"
-	"github.com/steinfletcher/apitest/mocks"
 	"io/ioutil"
 	"net/http"
 	"net/http/cookiejar"
@@ -11,6 +9,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/steinfletcher/apitest"
+	"github.com/steinfletcher/apitest/mocks"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -546,19 +547,17 @@ func TestApiTest_EndReturnsTheResult(t *testing.T) {
 	type resBody struct {
 		B string `json:"b"`
 	}
-	handler := http.NewServeMux()
-	handler.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusCreated)
-		w.Header().Set("Content-Type", "application/json")
-		_, err := w.Write([]byte(`{"a": 12345, "b": "hi"}`))
-		if err != nil {
-			panic(err)
-		}
-	})
 
 	var r resBody
 	apitest.New().
-		Handler(handler).
+		HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusCreated)
+			w.Header().Set("Content-Type", "application/json")
+			_, err := w.Write([]byte(`{"a": 12345, "b": "hi"}`))
+			if err != nil {
+				panic(err)
+			}
+		}).
 		Get("/hello").
 		Expect(t).
 		Body(`{
diff --git a/examples/go.sum b/examples/go.sum
index b283228..0e80249 100644
--- a/examples/go.sum
+++ b/examples/go.sum
@@ -159,6 +159,7 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/ugorji/go v1.1.2 h1:JON3E2/GPW2iDNGoSAusl1KDf5TRQ8k8q7Tp097pZGs=
 github.com/ugorji/go v1.1.2/go.mod h1:hnLbHMwcvSihnDhEfx2/BzKp2xb0Y+ErdfYcrs9tkJQ=
 github.com/ugorji/go/codec v0.0.0-20190126102652-8fd0f8d918c8 h1:X8lhf4a2HZiqw4DKNWz9aFZdssVV69au98QlhPXrEp8=