diff --git a/src/nucleus/response/stream.py b/src/nucleus/response/stream.py
index 87e054f..4f0b5d0 100644
--- a/src/nucleus/response/stream.py
+++ b/src/nucleus/response/stream.py
@@ -111,4 +111,6 @@ class ResponseStream:
             self.__next__ = stream_next
         elif isinstance(response.data, bytes):
             self.__next__ = bytes_next
+        else:
+            raise ValueError(type(response.data))
         return self