diff --git a/htmltest/options.go b/htmltest/options.go
index a38c880..e497cf7 100644
--- a/htmltest/options.go
+++ b/htmltest/options.go
@@ -2,12 +2,13 @@ package htmltest
 
 import (
 	"fmt"
-	"github.com/imdario/mergo"
-	"github.com/wjdp/htmltest/issues"
 	"path"
 	"reflect"
 	"regexp"
 	"strings"
+
+	"github.com/imdario/mergo"
+	"github.com/wjdp/htmltest/issues"
 )
 
 // Options struct for htmltest, user and default options are merged and mapped
@@ -113,7 +114,7 @@ func DefaultOptions() map[string]interface{} {
 		"IgnoreSSLVerify":                     false,
 		"IgnoreTagAttribute":                  "data-proofer-ignore",
 
-		"HTTPHeaders": map[string]string{
+		"HTTPHeaders": map[interface{}]interface{}{
 			"Range":  "bytes=0-0", // If server supports prevents body being sent
 			"Accept": "*/*",       // We accept all content types
 		},
@@ -145,9 +146,9 @@ func DefaultOptions() map[string]interface{} {
 func (hT *HTMLTest) setOptions(optsUser map[string]interface{}) {
 	// Merge user and default options, set Opts var
 	optsMap := DefaultOptions()
-	mergo.MergeWithOverwrite(&optsMap, optsUser)
+	mergo.Merge(&optsMap, optsUser, mergo.WithOverride)
 	hT.opts = Options{}
-	mergo.MapWithOverwrite(&hT.opts, optsMap)
+	mergo.Map(&hT.opts, optsMap, mergo.WithOverride)
 
 	// If debug dump the options struct
 	if hT.opts.LogLevel == issues.LevelDebug {
diff --git a/htmltest/options_test.go b/htmltest/options_test.go
index 95fc451..2cc4da5 100644
--- a/htmltest/options_test.go
+++ b/htmltest/options_test.go
@@ -1,9 +1,10 @@
 package htmltest
 
 import (
+	"testing"
+
 	"github.com/daviddengcn/go-assert"
 	"github.com/wjdp/htmltest/output"
-	"testing"
 )
 
 func TestDefaultOptions(t *testing.T) {
@@ -57,3 +58,18 @@ func TestIsURLIgnored(t *testing.T) {
 	assert.IsFalse(t, "url left alone", hT.opts.isURLIgnored("https://froogle.com/?q=1234"))
 	assert.IsFalse(t, "url left alone", hT.opts.isURLIgnored("http://assetstore.info/lib/test.js"))
 }
+
+func TestMergeHTTPHeaders(t *testing.T) {
+	userOpts := map[string]interface{}{
+		"HTTPHeaders": map[interface{}]interface{}{
+			"Range":  "bytes=0-10",
+			"Accept": "*/*",
+		},
+		"NoRun": true,
+	}
+
+	hT, err := Test(userOpts)
+	output.CheckErrorPanic(err)
+
+	assert.Equals(t, "url ignored", hT.opts.HTTPHeaders["Range"], "bytes=0-10")
+}