--- a/controllers/externalwfs.go	Thu Aug 09 13:11:35 2018 +0200
+++ b/controllers/externalwfs.go	Thu Aug 09 13:11:50 2018 +0200
@@ -194,12 +194,19 @@
 	return nil
 }
 
+var xmlContentTypes = []string{
+	"application/xml",
+	"text/xml",
+	"application/gml+xml",
+}
+
 func isXML(h http.Header) bool {
 	for _, t := range h["Content-Type"] {
 		t = strings.ToLower(t)
-		if strings.Contains(t, "text/xml") ||
-			strings.Contains(t, "application/xml") {
-			return true
+		for _, ct := range xmlContentTypes {
+			if strings.Contains(t, ct) {
+				return true
+			}
 		}
 	}
 	return false