diff --git a/coreapi/transports/http.py b/coreapi/transports/http.py
index a548024..ec34cea 100644
--- a/coreapi/transports/http.py
+++ b/coreapi/transports/http.py
@@ -268,6 +268,8 @@ def _coerce_to_error(obj, default_title):
         return Error(title=default_title, content={'messages': obj})
     elif obj is None:
         return Error(title=default_title)
+    elif hasattr(obj, "read"):
+        return Error(title=default_title, content={'messages': obj.read().decode("utf-8")})
     return Error(title=default_title, content={'message': obj})