diff --git a/jwt.go b/jwt.go
index 628bcb5..0f6cf0a 100644
--- a/jwt.go
+++ b/jwt.go
@@ -127,7 +127,12 @@ func Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
 
 	// Lookup key
 	var key interface{}
+	if keyFunc == nil {
+		// keyFunc was not provided.  short circuiting validation
+		return token, &ValidationError{err: "no Keyfunc was provided.", Errors: ValidationErrorUnverifiable}
+	}
 	if key, err = keyFunc(token); err != nil {
+		// keyFunc returned an error
 		return token, &ValidationError{err: err.Error(), Errors: ValidationErrorUnverifiable}
 	}
 
diff --git a/jwt_test.go b/jwt_test.go
index 5fc82fb..557c850 100644
--- a/jwt_test.go
+++ b/jwt_test.go
@@ -9,9 +9,18 @@ import (
 	"time"
 )
 
+var (
+	jwtTestDefaultKey []byte
+	defaultKeyFunc    Keyfunc = func(t *Token) (interface{}, error) { return jwtTestDefaultKey, nil }
+	emptyKeyFunc      Keyfunc = func(t *Token) (interface{}, error) { return nil, nil }
+	errorKeyFunc      Keyfunc = func(t *Token) (interface{}, error) { return nil, fmt.Errorf("error loading key") }
+	nilKeyFunc        Keyfunc = nil
+)
+
 var jwtTestData = []struct {
 	name            string
 	tokenString     string
+	keyfunc         Keyfunc
 	claims          map[string]interface{}
 	valid           bool
 	validationError *ValidationError
@@ -19,6 +28,7 @@ var jwtTestData = []struct {
 	{
 		"basic",
 		"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJmb28iOiJiYXIifQ.FhkiHkoESI_cG3NPigFrxEk9Z60_oXrOT2vGm9Pn6RDgYNovYORQmmA0zs1AoAOf09ly2Nx2YAg6ABqAYga1AcMFkJljwxTT5fYphTuqpWdy4BELeSYJx5Ty2gmr8e7RonuUztrdD5WfPqLKMm1Ozp_T6zALpRmwTIW0QPnaBXaQD90FplAg46Iy1UlDKr-Eupy0i5SLch5Q-p2ZpaL_5fnTIUDlxC3pWhJTyx_71qDI-mAA_5lE_VdroOeflG56sSmDxopPEG3bFlSu1eowyBfxtu0_CuVd-M42RU75Zc4Gsj6uV77MBtbMrf4_7M_NUTSgoIF3fRqxrj0NzihIBg",
+		defaultKeyFunc,
 		map[string]interface{}{"foo": "bar"},
 		true,
 		nil,
@@ -26,6 +36,7 @@ var jwtTestData = []struct {
 	{
 		"basic expired",
 		"", // autogen
+		defaultKeyFunc,
 		map[string]interface{}{"foo": "bar", "exp": float64(time.Now().Unix() - 100)},
 		false,
 		&ValidationError{Errors: ValidationErrorExpired},
@@ -33,6 +44,7 @@ var jwtTestData = []struct {
 	{
 		"basic nbf",
 		"", // autogen
+		defaultKeyFunc,
 		map[string]interface{}{"foo": "bar", "nbf": float64(time.Now().Unix() + 100)},
 		false,
 		&ValidationError{Errors: ValidationErrorNotValidYet},
@@ -40,6 +52,7 @@ var jwtTestData = []struct {
 	{
 		"expired and nbf",
 		"", // autogen
+		defaultKeyFunc,
 		map[string]interface{}{"foo": "bar", "nbf": float64(time.Now().Unix() + 100), "exp": float64(time.Now().Unix() - 100)},
 		false,
 		&ValidationError{Errors: ValidationErrorNotValidYet | ValidationErrorExpired},
@@ -47,10 +60,42 @@ var jwtTestData = []struct {
 	{
 		"basic invalid",
 		"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJmb28iOiJiYXIifQ.EhkiHkoESI_cG3NPigFrxEk9Z60_oXrOT2vGm9Pn6RDgYNovYORQmmA0zs1AoAOf09ly2Nx2YAg6ABqAYga1AcMFkJljwxTT5fYphTuqpWdy4BELeSYJx5Ty2gmr8e7RonuUztrdD5WfPqLKMm1Ozp_T6zALpRmwTIW0QPnaBXaQD90FplAg46Iy1UlDKr-Eupy0i5SLch5Q-p2ZpaL_5fnTIUDlxC3pWhJTyx_71qDI-mAA_5lE_VdroOeflG56sSmDxopPEG3bFlSu1eowyBfxtu0_CuVd-M42RU75Zc4Gsj6uV77MBtbMrf4_7M_NUTSgoIF3fRqxrj0NzihIBg",
+		defaultKeyFunc,
 		map[string]interface{}{"foo": "bar"},
 		false,
 		&ValidationError{Errors: ValidationErrorSignatureInvalid},
 	},
+	{
+		"basic nokeyfunc",
+		"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJmb28iOiJiYXIifQ.FhkiHkoESI_cG3NPigFrxEk9Z60_oXrOT2vGm9Pn6RDgYNovYORQmmA0zs1AoAOf09ly2Nx2YAg6ABqAYga1AcMFkJljwxTT5fYphTuqpWdy4BELeSYJx5Ty2gmr8e7RonuUztrdD5WfPqLKMm1Ozp_T6zALpRmwTIW0QPnaBXaQD90FplAg46Iy1UlDKr-Eupy0i5SLch5Q-p2ZpaL_5fnTIUDlxC3pWhJTyx_71qDI-mAA_5lE_VdroOeflG56sSmDxopPEG3bFlSu1eowyBfxtu0_CuVd-M42RU75Zc4Gsj6uV77MBtbMrf4_7M_NUTSgoIF3fRqxrj0NzihIBg",
+		nilKeyFunc,
+		map[string]interface{}{"foo": "bar"},
+		false,
+		&ValidationError{Errors: ValidationErrorUnverifiable},
+	},
+	{
+		"basic nokey",
+		"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJmb28iOiJiYXIifQ.FhkiHkoESI_cG3NPigFrxEk9Z60_oXrOT2vGm9Pn6RDgYNovYORQmmA0zs1AoAOf09ly2Nx2YAg6ABqAYga1AcMFkJljwxTT5fYphTuqpWdy4BELeSYJx5Ty2gmr8e7RonuUztrdD5WfPqLKMm1Ozp_T6zALpRmwTIW0QPnaBXaQD90FplAg46Iy1UlDKr-Eupy0i5SLch5Q-p2ZpaL_5fnTIUDlxC3pWhJTyx_71qDI-mAA_5lE_VdroOeflG56sSmDxopPEG3bFlSu1eowyBfxtu0_CuVd-M42RU75Zc4Gsj6uV77MBtbMrf4_7M_NUTSgoIF3fRqxrj0NzihIBg",
+		emptyKeyFunc,
+		map[string]interface{}{"foo": "bar"},
+		false,
+		&ValidationError{Errors: ValidationErrorSignatureInvalid},
+	},
+	{
+		"basic errorkey",
+		"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJmb28iOiJiYXIifQ.FhkiHkoESI_cG3NPigFrxEk9Z60_oXrOT2vGm9Pn6RDgYNovYORQmmA0zs1AoAOf09ly2Nx2YAg6ABqAYga1AcMFkJljwxTT5fYphTuqpWdy4BELeSYJx5Ty2gmr8e7RonuUztrdD5WfPqLKMm1Ozp_T6zALpRmwTIW0QPnaBXaQD90FplAg46Iy1UlDKr-Eupy0i5SLch5Q-p2ZpaL_5fnTIUDlxC3pWhJTyx_71qDI-mAA_5lE_VdroOeflG56sSmDxopPEG3bFlSu1eowyBfxtu0_CuVd-M42RU75Zc4Gsj6uV77MBtbMrf4_7M_NUTSgoIF3fRqxrj0NzihIBg",
+		errorKeyFunc,
+		map[string]interface{}{"foo": "bar"},
+		false,
+		&ValidationError{Errors: ValidationErrorUnverifiable},
+	},
+}
+
+func init() {
+	var e error
+	if jwtTestDefaultKey, e = ioutil.ReadFile("test/sample_key.pub"); e != nil {
+		panic(e)
+	}
 }
 
 func makeSample(c map[string]interface{}) string {
@@ -71,16 +116,11 @@ func makeSample(c map[string]interface{}) string {
 }
 
 func TestJWT(t *testing.T) {
-	key, e := ioutil.ReadFile("test/sample_key.pub")
-	if e != nil {
-		t.Fatal(e)
-	}
-
 	for _, data := range jwtTestData {
 		if data.tokenString == "" {
 			data.tokenString = makeSample(data.claims)
 		}
-		token, err := Parse(data.tokenString, func(t *Token) (interface{}, error) { return key, nil })
+		token, err := Parse(data.tokenString, data.keyfunc)
 
 		if !reflect.DeepEqual(data.claims, token.Claims) {
 			t.Errorf("[%v] Claims mismatch. Expecting: %v  Got: %v", data.name, data.claims, token.Claims)
@@ -107,11 +147,6 @@ func TestJWT(t *testing.T) {
 }
 
 func TestParseRequest(t *testing.T) {
-	key, e := ioutil.ReadFile("test/sample_key.pub")
-	if e != nil {
-		t.Fatal(e)
-	}
-
 	// Bearer token request
 	for _, data := range jwtTestData {
 		if data.tokenString == "" {
@@ -120,7 +155,7 @@ func TestParseRequest(t *testing.T) {
 
 		r, _ := http.NewRequest("GET", "/", nil)
 		r.Header.Set("Authorization", fmt.Sprintf("Bearer %v", data.tokenString))
-		token, err := ParseFromRequest(r, func(t *Token) (interface{}, error) { return key, nil })
+		token, err := ParseFromRequest(r, data.keyfunc)
 
 		if !reflect.DeepEqual(data.claims, token.Claims) {
 			t.Errorf("[%v] Claims mismatch. Expecting: %v  Got: %v", data.name, data.claims, token.Claims)