diff --git a/misc/python/materialize/parallel_workload/action.py b/misc/python/materialize/parallel_workload/action.py
index 6a008fc235834..c5678150d34c6 100644
--- a/misc/python/materialize/parallel_workload/action.py
+++ b/misc/python/materialize/parallel_workload/action.py
@@ -6249,6 +6249,9 @@ def errors_to_ignore(self, exe: Executor) -> list[str]:
                 'is not allowed from the "mz_catalog_server" cluster',
                 # Scanning persist part stats can outrun statement_timeout.
                 "canceling statement due to statement timeout",
+                # Under real-time recency the EXPLAIN waits for the source
+                # like a SELECT does, and can hit the RTR timeout (SS-303).
+                "timed out before ingesting the source's visible frontier when real-time-recency query issued",
             ]
         )
         if exe.db.complexity == Complexity.DDL: