diff --git a/assert/assertions.go b/assert/assertions.go
index 10c1992..fb2707f 100644
--- a/assert/assertions.go
+++ b/assert/assertions.go
@@ -173,8 +173,13 @@ func NotNil(t *testing.T, object interface{}, msgAndArgs ...interface{}) bool {
 
 	if object == nil {
 		success = false
-	} else if reflect.ValueOf(object).IsNil() {
-		success = false
+	}
+
+	val := reflect.ValueOf(object)
+	if val.CanAddr() {
+		if reflect.ValueOf(object).IsNil() {
+			success = false
+		}
 	}
 
 	if !success {
@@ -201,8 +206,13 @@ func Nil(t *testing.T, object interface{}, msgAndArgs ...interface{}) bool {
 
 	if object == nil {
 		return true
-	} else if reflect.ValueOf(object).IsNil() {
-		return true
+	}
+
+	val := reflect.ValueOf(object)
+	if val.CanAddr() {
+		if reflect.ValueOf(object).IsNil() {
+			return true
+		}
 	}
 
 	if len(message) > 0 {
diff --git a/assert/assertions_test.go b/assert/assertions_test.go
index c965173..7396dd3 100644
--- a/assert/assertions_test.go
+++ b/assert/assertions_test.go
@@ -5,6 +5,10 @@ import (
 	"testing"
 )
 
+type CustomError struct{}
+
+func (c CustomError) Error() string { return "Error" }
+
 // AssertionTesterInterface defines an interface to be used for testing assertion methods
 type AssertionTesterInterface interface {
 	TestMethod()
@@ -115,6 +119,54 @@ func TestNil(t *testing.T) {
 
 }
 
+func TestNil_ValueType(t *testing.T) {
+
+	f := func() AssertionTesterConformingObject {
+		return AssertionTesterConformingObject{}
+	}
+
+	mockT := new(testing.T)
+	obj := f()
+	False(t, Nil(mockT, obj))
+
+}
+
+func TestNil_ValueType_IsNil(t *testing.T) {
+
+	f := func() AssertionTesterInterface {
+		return nil
+	}
+
+	mockT := new(testing.T)
+	obj := f()
+	True(t, Nil(mockT, obj))
+
+}
+
+func TestNil_ValueError(t *testing.T) {
+
+	f := func() error {
+		return CustomError{}
+	}
+
+	mockT := new(testing.T)
+	obj := f()
+	False(t, Nil(mockT, obj))
+
+}
+
+func TestNotNil_ValueError(t *testing.T) {
+
+	f := func() error {
+		return CustomError{}
+	}
+
+	mockT := new(testing.T)
+	obj := f()
+	True(t, NotNil(mockT, obj))
+
+}
+
 func TestTrue(t *testing.T) {
 
 	mockT := new(testing.T)
@@ -333,3 +385,15 @@ func TestNotEmpty(t *testing.T) {
 	True(t, NotEmpty(mockT, true), "True value is not empty")
 
 }
+
+func TestEmpty_Value(t *testing.T) {
+
+	f := func() error {
+		return CustomError{}
+	}
+
+	mockT := new(testing.T)
+	obj := f()
+	False(t, Empty(mockT, obj))
+
+}