diff --git a/tests/test_utils_opmsg.py b/tests/test_utils_opmsg.py
index cd094f74f..eaf7ec8c9 100644
--- a/tests/test_utils_opmsg.py
+++ b/tests/test_utils_opmsg.py
@@ -24,14 +24,14 @@ def run_all_iocs():
                 mor.host(
                     **{f"{base}:STATUS": {"type": "enum", "enums": ["OFFLINE", "PREPARATION", "REMOTE", "ATTENDED"]}},
                     **{f"{base}:STATUS-DATE": str},
-                    **{f"{base}:OP-MSG-tmp": str},
+                    **{f"{base}:OP-MSG-TMP": str},
                     **{f"{base}:OP-DATE{i}": str for i in range(N_MSG_HISTORY)},
                     **{f"{base}:OP-MSG{i}":  str for i in range(N_MSG_HISTORY)},
                 )
                 mor.serve(
                     **{f"{base}:STATUS": "OFFLINE"},
                     **{f"{base}:STATUS-DATE": "2024-01-01 00:00:00"},
-                    **{f"{base}:OP-MSG-tmp": ""},
+                    **{f"{base}:OP-MSG-TMP": ""},
                     **{f"{base}:OP-DATE{i}": f"2024-01-01 00:00:0{i}" for i in range(N_MSG_HISTORY)},
                     **{f"{base}:OP-MSG{i}":  f"Initial message {i}" for i in range(N_MSG_HISTORY)},
                 )