From dfc80c70694c238ee64206106843879042e12d6a Mon Sep 17 00:00:00 2001
From: Jonathan Shimwell <mail@jshimwell.com>
Date: Wed, 7 Jan 2026 11:54:57 +0100
Subject: [PATCH] fixing temperatures setting for mgxs (#3712)

---
 openmc/mgxs_library.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/openmc/mgxs_library.py b/openmc/mgxs_library.py
index 414bf7cbd..c1a15998e 100644
--- a/openmc/mgxs_library.py
+++ b/openmc/mgxs_library.py
@@ -484,7 +484,8 @@ class XSdata:
 
         check_type('temperature', temperature, Real)
 
-        temp_store = self.temperatures.tolist().append(temperature)
+        temp_store = self.temperatures.tolist()
+        temp_store.append(temperature)
         self.temperatures = temp_store
 
         self._total.append(None)