diff --git a/sanic/testing.py b/sanic/testing.py
index 09554e21..de26d025 100644
--- a/sanic/testing.py
+++ b/sanic/testing.py
@@ -32,7 +32,9 @@ class SanicTestClient:
 
                 try:
                     response.json = await response.json()
-                except (JSONDecodeError, UnicodeDecodeError):
+                except (JSONDecodeError,
+                        UnicodeDecodeError,
+                        aiohttp.ClientResponseError):
                     response.json = None
 
                 response.body = await response.read()