diff --git a/README.md b/README.md
index f6b91a3..9ee8778 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ import (
 	. "gopkg.in/bluesuncorp/assert.v1"
 )
 
-func AssertCustomErrorHandler(t *testing.T, errs map[string]string, key, expected string) {
+func AssertCustomErrorHandler(t testing.TB, errs map[string]string, key, expected string) {
 	val, ok := errs[key]
 
 	// using EqualSkip and NotEqualSkip as building blocks for my custom Assert function
diff --git a/assert.go b/assert.go
index 9d272d0..d72c912 100644
--- a/assert.go
+++ b/assert.go
@@ -67,14 +67,14 @@ CASE4:
 }
 
 // Equal validates that val1 is equal to val2 and throws an error with line number
-func Equal(t *testing.T, val1, val2 interface{}) {
+func Equal(t testing.TB, val1, val2 interface{}) {
 	EqualSkip(t, 2, val1, val2)
 }
 
 // EqualSkip validates that val1 is equal to val2 and throws an error with line number
 // but the skip variable tells EqualSkip how far back on the stack to report the error.
 // This is a building block to creating your own more complex validation functions.
-func EqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
+func EqualSkip(t testing.TB, skip int, val1, val2 interface{}) {
 
 	if !IsEqual(val1, val2) {
 		_, file, line, _ := runtime.Caller(skip)
@@ -84,14 +84,14 @@ func EqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
 }
 
 // NotEqual validates that val1 is not equal val2 and throws an error with line number
-func NotEqual(t *testing.T, val1, val2 interface{}) {
+func NotEqual(t testing.TB, val1, val2 interface{}) {
 	NotEqualSkip(t, 2, val1, val2)
 }
 
 // NotEqualSkip validates that val1 is not equal to val2 and throws an error with line number
 // but the skip variable tells NotEqualSkip how far back on the stack to report the error.
 // This is a building block to creating your own more complex validation functions.
-func NotEqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
+func NotEqualSkip(t testing.TB, skip int, val1, val2 interface{}) {
 
 	if IsEqual(val1, val2) {
 		_, file, line, _ := runtime.Caller(skip)
@@ -101,14 +101,14 @@ func NotEqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
 }
 
 // PanicMatches validates that the panic output of running fn matches the supplied string
-func PanicMatches(t *testing.T, fn func(), matches string) {
+func PanicMatches(t testing.TB, fn func(), matches string) {
 	PanicMatchesSkip(t, 2, fn, matches)
 }
 
 // PanicMatchesSkip validates that the panic output of running fn matches the supplied string
 // but the skip variable tells PanicMatchesSkip how far back on the stack to report the error.
 // This is a building block to creating your own more complex validation functions.
-func PanicMatchesSkip(t *testing.T, skip int, fn func(), matches string) {
+func PanicMatchesSkip(t testing.TB, skip int, fn func(), matches string) {
 
 	_, file, line, _ := runtime.Caller(skip)
 
diff --git a/assert_test.go b/assert_test.go
index cd798f5..ebd8d48 100644
--- a/assert_test.go
+++ b/assert_test.go
@@ -16,7 +16,7 @@ import (
 // go test -coverprofile cover.out && go tool cover -html=cover.out -o cover.html
 //
 
-func MyCustomErrorHandler(t *testing.T, errs map[string]string, key, expected string) {
+func MyCustomErrorHandler(t testing.TB, errs map[string]string, key, expected string) {
 	val, ok := errs[key]
 	EqualSkip(t, 2, ok, true)
 	NotEqualSkip(t, 2, val, nil)
diff --git a/doc.go b/doc.go
index cd71815..f13586c 100644
--- a/doc.go
+++ b/doc.go
@@ -11,7 +11,7 @@ validations.
 		. "gopkg.in/bluesuncorp/assert.v1"
 	)
 
-	func AssertCustomErrorHandler(t *testing.T, errs map[string]string, key, expected string) {
+	func AssertCustomErrorHandler(t testing.TB, errs map[string]string, key, expected string) {
 		val, ok := errs[key]
 
 		// using EqualSkip and NotEqualSkip as building blocks for my custom Assert function