diff --git a/src/test.rs b/src/test.rs
index ee51b71ee..8f4047fae 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -270,7 +270,7 @@ where
     let body = read_body(res).await;
 
     serde_json::from_slice(&body)
-        .unwrap_or_else(|_| panic!("read_response_json failed during deserialization"))
+        .unwrap_or_else(|e| panic!("read_response_json failed during deserialization: {}", e))
 }
 
 pub async fn load_stream<S>(mut stream: S) -> Result<Bytes, Error>