diff --git a/source/handy_http_primitives/optional.d b/source/handy_http_primitives/optional.d
index e90f0ea..e83f549 100644
--- a/source/handy_http_primitives/optional.d
+++ b/source/handy_http_primitives/optional.d
@@ -127,7 +127,7 @@ struct Optional(T) {
                 if (this.isNull) {
                     serializer.putValue(null);
                 } else {
-                    serializer.putValue(this.value);
+                    serializeValue(serializer, this.value);
                 }
             }
         }