diff --git a/src/script_opt/FuncInfo.cc b/src/script_opt/FuncInfo.cc
index c21586f406..b244a7753c 100644
--- a/src/script_opt/FuncInfo.cc
+++ b/src/script_opt/FuncInfo.cc
@@ -72,6 +72,7 @@ static std::unordered_map<std::string, unsigned int> func_attrs = {
     {"Analyzer::__register_for_port", ATTR_NO_SCRIPT_SIDE_EFFECTS},
     {"Analyzer::__schedule_analyzer", ATTR_NO_SCRIPT_SIDE_EFFECTS},
     {"Analyzer::__tag", ATTR_FOLDABLE},
+    {"Cluster::Backend::ZeroMQ::spawn_zmq_proxy_thread", ATTR_NO_SCRIPT_SIDE_EFFECTS},
     {"Cluster::Backend::__init", ATTR_NO_SCRIPT_SIDE_EFFECTS},
     {"Cluster::__subscribe", ATTR_NO_SCRIPT_SIDE_EFFECTS},
     {"Cluster::__unsubscribe", ATTR_NO_SCRIPT_SIDE_EFFECTS},
diff --git a/testing/btest/Baseline/opt.ZAM-bif-tracking/output b/testing/btest/Baseline/opt.ZAM-bif-tracking/output
index d17a83be72..fc17f81c25 100644
--- a/testing/btest/Baseline/opt.ZAM-bif-tracking/output
+++ b/testing/btest/Baseline/opt.ZAM-bif-tracking/output
@@ -1,2 +1,2 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-541 seen BiFs, 0 unseen BiFs (), 0 new BiFs ()
+542 seen BiFs, 0 unseen BiFs (), 0 new BiFs ()
diff --git a/testing/btest/opt/ZAM-bif-tracking.zeek b/testing/btest/opt/ZAM-bif-tracking.zeek
index e886fb1ce0..1e46d837f1 100644
--- a/testing/btest/opt/ZAM-bif-tracking.zeek
+++ b/testing/btest/opt/ZAM-bif-tracking.zeek
@@ -1,6 +1,7 @@
 # @TEST-DOC: ZAM maintenance script for tracking changes in BiFs.
 #
 # @TEST-REQUIRES: have-spicy
+# @TEST-REQUIRES: have-zeromq
 #
 # @TEST-EXEC: zeek -b %INPUT >output
 # @TEST-EXEC: btest-diff output
@@ -198,6 +199,7 @@ global known_BiFs = set(
 	"Telemetry::__histogram_observe",
 	"Telemetry::__histogram_sum",
 	"WebSocket::__configure_analyzer",
+	"Cluster::Backend::ZeroMQ::spawn_zmq_proxy_thread",
 	"__init_primary_bifs",
 	"__init_secondary_bifs",
 	"active_file",