diff --git a/utils/http.go b/utils/http.go
index 02498aede3..fe394f518a 100644
--- a/utils/http.go
+++ b/utils/http.go
@@ -5,6 +5,7 @@
 package utils
 
 import (
+	"mime"
 	"strings"
 )
 
@@ -15,16 +16,25 @@ func GetMIME(extension string) string {
 	if len(extension) == 0 {
 		return ""
 	}
-	var mime string
+	var foundMime string
 	if extension[0] == '.' {
-		mime = mimeExtensions[extension[1:]]
+		foundMime = mimeExtensions[extension[1:]]
 	} else {
-		mime = mimeExtensions[extension]
+		foundMime = mimeExtensions[extension]
 	}
-	if len(mime) == 0 {
-		return MIMEOctetStream
+
+	if len(foundMime) == 0 {
+		if extension[0] != '.' {
+			foundMime = mime.TypeByExtension("." + extension)
+		} else {
+			foundMime = mime.TypeByExtension(extension)
+		}
+
+		if foundMime == "" {
+			return MIMEOctetStream
+		}
 	}
-	return mime
+	return foundMime
 }
 
 // ParseVendorSpecificContentType check if content type is vendor specific and
diff --git a/utils/http_test.go b/utils/http_test.go
index 2abe6c51a4..56a6029639 100644
--- a/utils/http_test.go
+++ b/utils/http_test.go
@@ -23,6 +23,14 @@ func Test_GetMIME(t *testing.T) {
 
 	res = GetMIME("unknown")
 	AssertEqual(t, MIMEOctetStream, res)
+
+	err := mime.AddExtensionType(".mjs", "application/javascript")
+	if err == nil {
+		res = GetMIME(".mjs")
+		AssertEqual(t, "application/javascript", res)
+	}
+	AssertEqual(t, nil, err)
+
 	// empty case
 	res = GetMIME("")
 	AssertEqual(t, "", res)