diff --git a/puppet/zulip/files/nagios_plugins/zulip_postgresql/check_postgresql_replication_lag b/puppet/zulip/files/nagios_plugins/zulip_postgresql/check_postgresql_replication_lag
index 5be56dff58..5548b7b98b 100755
--- a/puppet/zulip/files/nagios_plugins/zulip_postgresql/check_postgresql_replication_lag
+++ b/puppet/zulip/files/nagios_plugins/zulip_postgresql/check_postgresql_replication_lag
@@ -95,7 +95,7 @@ else:
     replication_info = run_sql_query(
         "client_addr, state, sent_lsn, write_lsn, flush_lsn, replay_lsn from pg_stat_replication"
     )
-    if replication_info == 0:
+    if not replication_info:
         report("CRITICAL", "No replicas!")
     elif len(replication_info) == 1:
         report("WARNING", "Only one replica!")
diff --git a/zerver/lib/test_classes.py b/zerver/lib/test_classes.py
index 23c28fff9d..613bd96c83 100644
--- a/zerver/lib/test_classes.py
+++ b/zerver/lib/test_classes.py
@@ -849,7 +849,7 @@ Output:
         self.assertNotEqual(json["msg"], "Error parsing JSON in response!")
         return json
 
-    def get_json_error(self, result: HttpResponse, status_code: int = 400) -> Dict[str, Any]:
+    def get_json_error(self, result: HttpResponse, status_code: int = 400) -> str:
         try:
             json = orjson.loads(result.content)
         except orjson.JSONDecodeError:  # nocoverage