diff --git a/testing/btest/Baseline/plugins.publish-event-metadata/manager..stderr b/testing/btest/Baseline/plugins.publish-event-metadata/manager..stderr
new file mode 100644
index 0000000000..e3f6131b1d
--- /dev/null
+++ b/testing/btest/Baseline/plugins.publish-event-metadata/manager..stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+received termination signal
diff --git a/testing/btest/Baseline/plugins.publish-event-metadata/manager..stdout b/testing/btest/Baseline/plugins.publish-event-metadata/manager..stdout
new file mode 100644
index 0000000000..902f2cf0d0
--- /dev/null
+++ b/testing/btest/Baseline/plugins.publish-event-metadata/manager..stdout
@@ -0,0 +1,33 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+0.000000   InitPostScript
+App::test_event(1) |mdv|=1
+[id=App::CUSTOM_METADATA_STRING, val=testing string metadata]
+custom metadata string, [testing string metadata]
+custom metadata count, []
+custom metadata table, []
+App::test_event(2) |mdv|=1
+[id=App::CUSTOM_METADATA_COUNT, val=42424242]
+custom metadata string, []
+custom metadata count, [42424242]
+custom metadata table, []
+App::test_event(3) |mdv|=1
+[id=App::CUSTOM_METADATA_TABLE, val={
+[key1] = val1
+}]
+custom metadata string, []
+custom metadata count, []
+custom metadata table, [{
+[key1] = val1
+}]
+App::test_event(4) |mdv|=4
+[id=App::CUSTOM_METADATA_TABLE, val={
+[key1] = val1
+}]
+[id=App::CUSTOM_METADATA_COUNT, val=41414242]
+[id=App::CUSTOM_METADATA_STRING, val=testing string metadata]
+[id=App::CUSTOM_METADATA_STRING, val=more string metadata]
+custom metadata string, [testing string metadata, more string metadata]
+custom metadata count, [41414242]
+custom metadata table, [{
+[key1] = val1
+}]
diff --git a/testing/btest/Baseline/plugins.publish-event-metadata/output b/testing/btest/Baseline/plugins.publish-event-metadata/output
new file mode 100644
index 0000000000..b88529121f
--- /dev/null
+++ b/testing/btest/Baseline/plugins.publish-event-metadata/output
@@ -0,0 +1,4 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+0.000000   InitPostScript
+0.000000   HookPublishEvent backend=Broker topic=/test/topic event=App::test_event
+0.000000   HookPublishEvent /test/topic(App::test_event)
diff --git a/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stderr b/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stderr
new file mode 100644
index 0000000000..e3f6131b1d
--- /dev/null
+++ b/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+received termination signal
diff --git a/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stdout b/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stdout
new file mode 100644
index 0000000000..3abd76e59f
--- /dev/null
+++ b/testing/btest/Baseline/plugins.publish-event-metadata/worker-1..stdout
@@ -0,0 +1,6 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+0.000000   InitPostScript
+0.000000   HookPublishEvent backend=Broker topic=topic1 event=App::test_event
+0.000000   HookPublishEvent backend=Broker topic=topic2 event=App::test_event
+0.000000   HookPublishEvent backend=Broker topic=topic3 event=App::test_event
+0.000000   HookPublishEvent backend=Broker topic=topic4 event=App::test_event
diff --git a/testing/btest/plugins/publish-event-metadata-plugin/src/Plugin.cc b/testing/btest/plugins/publish-event-metadata-plugin/src/Plugin.cc
index 5884e2d3ec..af615a38d2 100644
--- a/testing/btest/plugins/publish-event-metadata-plugin/src/Plugin.cc
+++ b/testing/btest/plugins/publish-event-metadata-plugin/src/Plugin.cc
@@ -65,6 +65,19 @@ bool Plugin::HookPublishEvent(zeek::cluster::Backend& backend, const std::string
         if ( ! event.AddMetadata(table_md, tv) ) {
             zeek::reporter->FatalError("Failed to add table metadata");
         }
+
+        if ( ! event.AddMetadata(count_md, zeek::val_mgr->Count(41414242)) ) {
+            zeek::reporter->FatalError("Failed to add string metadata");
+        }
+
+        if ( ! event.AddMetadata(string_md, zeek::make_intrusive<zeek::StringVal>("testing string metadata")) ) {
+            zeek::reporter->FatalError("Failed to add string metadata");
+        }
+
+        // metadata is just a vector, so can have duplicate entries.
+        if ( ! event.AddMetadata(string_md, zeek::make_intrusive<zeek::StringVal>("more string metadata")) ) {
+            zeek::reporter->FatalError("Failed to add string metadata");
+        }
     }
     else {
         zeek::reporter->FatalError("Unhandled topic %s", topic.c_str());