diff --git a/presigned.go b/presigned.go
index 937a59b..a39000b 100644
--- a/presigned.go
+++ b/presigned.go
@@ -14,6 +14,7 @@ import (
 
 const (
 	defaultPresignedURLFormat = "%s.s3.amazonaws.com" // <bucket>
+	defaultProtocol           = "https://"            // <bucket>
 )
 
 // PresignedInput is passed to GeneratePresignedURL as a parameter.
@@ -24,6 +25,7 @@ type PresignedInput struct {
 	Timestamp     time.Time
 	ExtraHeaders  map[string]string
 	ExpirySeconds int
+	Protocol      string
 }
 
 // GeneratePresignedURL creates a Presigned URL that can be used
@@ -31,12 +33,18 @@ type PresignedInput struct {
 // (https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html)
 func (s3 *S3) GeneratePresignedURL(in PresignedInput) string {
 	var (
-		nowTime = in.Timestamp.UTC()
-		cred    = fmt.Sprintf("%s/"+s3.buildCredentialWithoutKey(nowTime), s3.AccessKey)
-		amzdate = nowTime.Format(amzDateISO8601TimeFormat)
-		expiry  = strconv.Itoa(in.ExpirySeconds)
+		nowTime  = in.Timestamp.UTC()
+		cred     = fmt.Sprintf("%s/"+s3.buildCredentialWithoutKey(nowTime), s3.AccessKey)
+		amzdate  = nowTime.Format(amzDateISO8601TimeFormat)
+		expiry   = strconv.Itoa(in.ExpirySeconds)
+		protocol = in.Protocol
 	)
 
+	// Set the protocol as default if not provided.
+	if protocol == "" {
+		protocol = defaultProtocol
+	}
+
 	// Add host to Headers
 	signedHeaders := in.ExtraHeaders
 	if signedHeaders == nil {
@@ -151,7 +159,7 @@ func (s3 *S3) GeneratePresignedURL(in PresignedInput) string {
 	b.Reset()
 
 	// Start Generating URL
-	fmt.Fprintf(&b, "http://"+defaultPresignedURLFormat+"/", in.Bucket)
+	fmt.Fprintf(&b, protocol+defaultPresignedURLFormat+"/", in.Bucket)
 	fmt.Fprintf(&b, "%s?", in.ObjectKey)
 
 	// We don't need to have a sorted order here,
diff --git a/presigned_test.go b/presigned_test.go
index 1708eca..42f8556 100644
--- a/presigned_test.go
+++ b/presigned_test.go
@@ -16,7 +16,7 @@ func TestS3_GeneratePresignedURL(t *testing.T) {
 			"AKIAIOSFODNN7EXAMPLE",
 			"wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
 		)
-		want := "http://examplebucket.s3.amazonaws.com/test.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIOSFODNN7EXAMPLE%2F20130524%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20130524T000000Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host&X-Amz-Signature=aeeed9bbccd4d02ee5c0109b86d86835f995330da4c265957d157751f604d404"
+		want := "https://examplebucket.s3.amazonaws.com/test.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIOSFODNN7EXAMPLE%2F20130524%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20130524T000000Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host&X-Amz-Signature=aeeed9bbccd4d02ee5c0109b86d86835f995330da4c265957d157751f604d404"
 		if got := s.GeneratePresignedURL(PresignedInput{
 			Bucket:        "examplebucket",
 			ObjectKey:     "test.txt",