diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 6be2a52745..7919dc6f09 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -1363,7 +1363,11 @@ mod tests {
             serde_json::from_str(raw).unwrap_or_else(|err| panic!("failed to parse {case}: {err}"));
         let serialized = serde_json::to_value(&parsed)
             .unwrap_or_else(|err| panic!("failed to serialize {case}: {err}"));
-        assert_eq!(serialized, expected, "case {case} failed round trip");
+        assert_eq!(
+            normalize_rollout_value(serialized),
+            normalize_rollout_value(expected),
+            "case {case} failed round trip",
+        );
     }
 
     #[test]
diff --git a/codex-rs/protocol/tests/fixtures/rollouts/response_item/function_call_output.json b/codex-rs/protocol/tests/fixtures/rollouts/response_item/function_call_output.json
index 00e021107a..19cea72a6f 100644
--- a/codex-rs/protocol/tests/fixtures/rollouts/response_item/function_call_output.json
+++ b/codex-rs/protocol/tests/fixtures/rollouts/response_item/function_call_output.json
@@ -4,9 +4,6 @@
   "payload": {
     "type": "function_call_output",
     "call_id": "call-123",
-    "output": {
-      "content": "{\"stdout\":\"done\"}",
-      "success": null
-    }
+    "output": "{\"stdout\":\"done\"}"
   }
 }