diff --git a/CHANGES.md b/CHANGES.md
index 5c887595997..4a884b9c04b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -25,6 +25,10 @@ management and does not bundle Jinja2.
 
 ## __cylc-7.8.15 (Upcoming)__
 
+[#6569](https://github.com/cylc/cylc-flow/pull/6569) -
+Update PBS job runner to reflect error message change. This change
+continues to support older PBS versions.
+
 
 ## __cylc-7.8.14 (2023-01-15)__
 
diff --git a/lib/cylc/batch_sys_handlers/pbs.py b/lib/cylc/batch_sys_handlers/pbs.py
index 8b4d9c379aa..6327837e41b 100644
--- a/lib/cylc/batch_sys_handlers/pbs.py
+++ b/lib/cylc/batch_sys_handlers/pbs.py
@@ -39,7 +39,7 @@ class PBSHandler(object):
     # N.B. The "qstat JOB_ID" command returns 1 if JOB_ID is no longer in the
     # system, so there is no need to filter its output.
     POLL_CMD = "qstat"
-    POLL_CANT_CONNECT_ERR = "Connection refused"
+    POLL_CANT_CONNECT_ERR = "cannot connect to server"
     REC_ID_FROM_SUBMIT_OUT = re.compile(r"""\A\s*(?P<id>\S+)\s*\Z""")
     SUBMIT_CMD_TMPL = "qsub '%(job)s'"