diff --git a/src/input/ReaderBackend.cc b/src/input/ReaderBackend.cc
index 7645161e41..cb25cfda3e 100644
--- a/src/input/ReaderBackend.cc
+++ b/src/input/ReaderBackend.cc
@@ -257,7 +257,7 @@ bool ReaderBackend::Init(const int arg_num_fields,
 
 	disabled = false;
 
-	SetOSName(Fmt("bro: %s", Name()));
+	SetOSName(Fmt("zk.%s", Name()));
 
 	num_fields = arg_num_fields;
 	fields = arg_fields;
diff --git a/src/logging/WriterBackend.cc b/src/logging/WriterBackend.cc
index 162b19d26a..23fc855019 100644
--- a/src/logging/WriterBackend.cc
+++ b/src/logging/WriterBackend.cc
@@ -179,7 +179,7 @@ void WriterBackend::DisableFrontend()
 
 bool WriterBackend::Init(int arg_num_fields, const Field* const* arg_fields)
 	{
-	SetOSName(Fmt("bro: %s", Name()));
+	SetOSName(Fmt("zk.%s", Name()));
 	num_fields = arg_num_fields;
 	fields = arg_fields;