diff --git a/src/Conn.cc b/src/Conn.cc
index d2054d8f0d..c536ae06b4 100644
--- a/src/Conn.cc
+++ b/src/Conn.cc
@@ -285,7 +285,7 @@ void Connection::InactivityTimer(double t)
 		{
 		Event(connection_timeout, nullptr);
 		sessions->Remove(this);
-		++killed_by_inactivity;
+		++zeek::detail::killed_by_inactivity;
 		}
 	else
 		ADD_TIMER(&Connection::InactivityTimer,
diff --git a/src/Event.cc b/src/Event.cc
index 0bac0e6c4f..4792f79326 100644
--- a/src/Event.cc
+++ b/src/Event.cc
@@ -160,7 +160,7 @@ void EventMgr::Drain()
 	if ( event_queue_flush_point )
 		Enqueue(event_queue_flush_point, zeek::Args{});
 
-	SegmentProfiler prof(segment_logger, "draining-events");
+	zeek::detail::SegmentProfiler prof(zeek::detail::segment_logger, "draining-events");
 
 	PLUGIN_HOOK_VOID(HOOK_DRAIN_EVENTS, HookDrainEvents());
 
diff --git a/src/Net.cc b/src/Net.cc
index 7ae10f834c..e9e7734e9a 100644
--- a/src/Net.cc
+++ b/src/Net.cc
@@ -212,7 +212,7 @@ void net_init(const std::optional<std::string>& interface,
 
 void expire_timers(iosource::PktSrc* src_ps)
 	{
-	SegmentProfiler prof(segment_logger, "expiring-timers");
+	zeek::detail::SegmentProfiler prof(zeek::detail::segment_logger, "expiring-timers");
 
 	current_dispatched +=
 		zeek::detail::timer_mgr->Advance(network_time,
@@ -238,7 +238,7 @@ void net_packet_dispatch(double t, const zeek::Packet* pkt, iosource::PktSrc* sr
 
 	expire_timers(src_ps);
 
-	SegmentProfiler* sp = nullptr;
+	zeek::detail::SegmentProfiler* sp = nullptr;
 
 	if ( load_sample )
 		{
@@ -253,8 +253,8 @@ void net_packet_dispatch(double t, const zeek::Packet* pkt, iosource::PktSrc* sr
 			// charged against this sample.
 			zeek::event_mgr.Drain();
 
-			sample_logger = new SampleLogger();
-			sp = new SegmentProfiler(sample_logger, "load-samp");
+			zeek::detail::sample_logger = new zeek::detail::SampleLogger();
+			sp = new zeek::detail::SegmentProfiler(zeek::detail::sample_logger, "load-samp");
 			}
 		}
 
@@ -264,8 +264,8 @@ void net_packet_dispatch(double t, const zeek::Packet* pkt, iosource::PktSrc* sr
 	if ( sp )
 		{
 		delete sp;
-		delete sample_logger;
-		sample_logger = nullptr;
+		delete zeek::detail::sample_logger;
+		zeek::detail::sample_logger = nullptr;
 		}
 
 	processing_start_time = 0.0;	// = "we're not processing now"
diff --git a/src/Sessions.cc b/src/Sessions.cc
index 6b55bde85a..bc0a83ed87 100644
--- a/src/Sessions.cc
+++ b/src/Sessions.cc
@@ -84,7 +84,7 @@ NetSessions::NetSessions()
 	static auto pkt_profile_file = zeek::id::find_val("pkt_profile_file");
 
 	if ( pkt_profile_mode && pkt_profile_freq > 0 && pkt_profile_file )
-		pkt_profiler = new PacketProfiler(pkt_profile_mode,
+		pkt_profiler = new zeek::detail::PacketProfiler(pkt_profile_mode,
 				pkt_profile_freq, pkt_profile_file->AsFile());
 	else
 		pkt_profiler = nullptr;
@@ -121,7 +121,7 @@ void NetSessions::Done()
 
 void NetSessions::NextPacket(double t, const zeek::Packet* pkt)
 	{
-	SegmentProfiler prof(segment_logger, "dispatching-packet");
+	zeek::detail::SegmentProfiler prof(zeek::detail::segment_logger, "dispatching-packet");
 
 	if ( raw_packet )
 		zeek::event_mgr.Enqueue(raw_packet, pkt->ToRawPktHdrVal());
diff --git a/src/Sessions.h b/src/Sessions.h
index e68e4479db..f075551b2f 100644
--- a/src/Sessions.h
+++ b/src/Sessions.h
@@ -15,7 +15,7 @@
 ZEEK_FORWARD_DECLARE_NAMESPACED(EncapsulationStack, zeek);
 ZEEK_FORWARD_DECLARE_NAMESPACED(EncapsulatingConn, zeek);
 ZEEK_FORWARD_DECLARE_NAMESPACED(Packet, zeek);
-class PacketProfiler;
+ZEEK_FORWARD_DECLARE_NAMESPACED(PacketProfiler, zeek::detail);
 class Connection;
 class ConnCompressor;
 struct ConnID;
@@ -235,7 +235,7 @@ protected:
 	zeek::detail::Discarder* discarder;
 	zeek::detail::PacketFilter* packet_filter;
 	uint64_t num_packets_processed;
-	PacketProfiler* pkt_profiler;
+	zeek::detail::PacketProfiler* pkt_profiler;
 	bool dump_this_packet;	// if true, current packet should be recorded
 };
 
diff --git a/src/Stats.cc b/src/Stats.cc
index ba59130275..26cd4af2fa 100644
--- a/src/Stats.cc
+++ b/src/Stats.cc
@@ -15,13 +15,19 @@
 #include "input.h"
 #include "Func.h"
 
-uint64_t killed_by_inactivity = 0;
+uint64_t zeek::detail::killed_by_inactivity = 0;
+uint64_t& killed_by_inactivity = zeek::detail::killed_by_inactivity;
 
-uint64_t tot_ack_events = 0;
-uint64_t tot_ack_bytes = 0;
-uint64_t tot_gap_events = 0;
-uint64_t tot_gap_bytes = 0;
+uint64_t zeek::detail::tot_ack_events = 0;
+uint64_t& tot_ack_events = zeek::detail::tot_ack_events;
+uint64_t zeek::detail::tot_ack_bytes = 0;
+uint64_t& tot_ack_bytes = zeek::detail::tot_ack_bytes;
+uint64_t zeek::detail::tot_gap_events = 0;
+uint64_t& tot_gap_events = zeek::detail::tot_gap_events;
+uint64_t zeek::detail::tot_gap_bytes = 0;
+uint64_t& tot_gap_bytes = zeek::detail::tot_gap_bytes;
 
+namespace zeek::detail {
 
 class ProfileTimer final : public zeek::detail::Timer {
 public:
@@ -482,3 +488,5 @@ void PacketProfiler::ProfilePkt(double t, unsigned int bytes)
 	byte_cnt += bytes;
 	time = t;
 	}
+
+} // namespace zeek::detail
diff --git a/src/Stats.h b/src/Stats.h
index 1c5254b09a..85e22a19e4 100644
--- a/src/Stats.h
+++ b/src/Stats.h
@@ -16,6 +16,8 @@ ZEEK_FORWARD_DECLARE_NAMESPACED(Func, zeek);
 ZEEK_FORWARD_DECLARE_NAMESPACED(TableVal, zeek);
 ZEEK_FORWARD_DECLARE_NAMESPACED(Location, zeek::detail);
 
+namespace zeek::detail {
+
 // Object called by SegmentProfiler when it is done and reports its
 // cumulative CPU/memory statistics.
 class SegmentStatsReporter {
@@ -140,3 +142,24 @@ protected:
 	uint64_t pkt_cnt;
 	uint64_t byte_cnt;
 };
+
+} // namespace zeek::detail
+
+using SegmentStatsReporter [[deprecated("Remove in v4.1. Use zeek::detail::SegmentStatsReporter.")]] = zeek::detail::SegmentStatsReporter;
+using SegmentProfiler [[deprecated("Remove in v4.1. Use zeek::detail::SegmentProfiler.")]] = zeek::detail::SegmentProfiler;
+using ProfileLogger [[deprecated("Remove in v4.1. Use zeek::detail::ProfileLogger.")]] = zeek::detail::ProfileLogger;
+using SampleLogger [[deprecated("Remove in v4.1. Use zeek::detail::SampleLogger.")]] = zeek::detail::SampleLogger;
+using PacketProfiler [[deprecated("Remove in v4.1. Use zeek::detail::PacketProfiler.")]] = zeek::detail::PacketProfiler;
+
+extern zeek::detail::ProfileLogger*& profiling_logger [[deprecated("Remove in v4.1. Use zeek::detail::profiling_logger.")]];
+extern zeek::detail::ProfileLogger*& segment_logger [[deprecated("Remove in v4.1. Use zeek::detail::segment_logger.")]];
+extern zeek::detail::SampleLogger*& sample_logger [[deprecated("Remove in v4.1. Use zeek::detail::sample_logger.")]];
+
+// Connection statistics.
+extern uint64_t& killed_by_inactivity [[deprecated("Remove in v4.1. Use zeek::detail::killed_by_inactivity.")]];
+
+// Content gap statistics.
+extern uint64_t& tot_ack_events [[deprecated("Remove in v4.1. Use zeek::detail::tot_ack_events.")]];
+extern uint64_t& tot_ack_bytes [[deprecated("Remove in v4.1. Use zeek::detail::tot_ack_bytes.")]];
+extern uint64_t& tot_gap_events [[deprecated("Remove in v4.1. Use zeek::detail::tot_gap_events.")]];
+extern uint64_t& tot_gap_bytes [[deprecated("Remove in v4.1. Use zeek::detail::tot_gap_bytes.")]];
diff --git a/src/analyzer/protocol/tcp/TCP_Reassembler.cc b/src/analyzer/protocol/tcp/TCP_Reassembler.cc
index 7f43b64353..101e1dc93b 100644
--- a/src/analyzer/protocol/tcp/TCP_Reassembler.cc
+++ b/src/analyzer/protocol/tcp/TCP_Reassembler.cc
@@ -542,13 +542,13 @@ void TCP_Reassembler::AckReceived(uint64_t seq)
 
 	if ( test_active )
 		{
-		++tot_ack_events;
-		tot_ack_bytes += seq - trim_seq;
+		++zeek::detail::tot_ack_events;
+		zeek::detail::tot_ack_bytes += seq - trim_seq;
 
 		if ( num_missing > 0 )
 			{
-			++tot_gap_events;
-			tot_gap_bytes += num_missing;
+			++zeek::detail::tot_gap_events;
+			zeek::detail::tot_gap_bytes += num_missing;
 			}
 		}
 
diff --git a/src/main.cc b/src/main.cc
index 63741b469f..cdabc30176 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -22,8 +22,8 @@ int main(int argc, char** argv)
 
 	if ( do_net_run )
 		{
-		if ( profiling_logger )
-			profiling_logger->Log();
+		if ( zeek::detail::profiling_logger )
+			zeek::detail::profiling_logger->Log();
 
 #ifdef USE_PERFTOOLS_DEBUG
 		if ( perftools_leaks )
diff --git a/src/stats.bif b/src/stats.bif
index da453ae9e0..34f131c4cf 100644
--- a/src/stats.bif
+++ b/src/stats.bif
@@ -110,7 +110,7 @@ function get_conn_stats%(%): ConnStats
 	ADD_STAT(s.max_ICMP_conns);
 	ADD_STAT(s.cumulative_ICMP_conns);
 
-	r->Assign(n++, zeek::val_mgr->Count(killed_by_inactivity));
+	r->Assign(n++, zeek::val_mgr->Count(zeek::detail::killed_by_inactivity));
 
 	return r;
 	%}
@@ -365,10 +365,10 @@ function get_gap_stats%(%): GapStats
 	auto r = zeek::make_intrusive<zeek::RecordVal>(GapStats);
 	int n = 0;
 
-	r->Assign(n++, zeek::val_mgr->Count(tot_ack_events));
-	r->Assign(n++, zeek::val_mgr->Count(tot_ack_bytes));
-	r->Assign(n++, zeek::val_mgr->Count(tot_gap_events));
-	r->Assign(n++, zeek::val_mgr->Count(tot_gap_bytes));
+	r->Assign(n++, zeek::val_mgr->Count(zeek::detail::tot_ack_events));
+	r->Assign(n++, zeek::val_mgr->Count(zeek::detail::tot_ack_bytes));
+	r->Assign(n++, zeek::val_mgr->Count(zeek::detail::tot_gap_events));
+	r->Assign(n++, zeek::val_mgr->Count(zeek::detail::tot_gap_bytes));
 
 	return r;
 	%}
diff --git a/src/zeek-setup.cc b/src/zeek-setup.cc
index b4d2ee6f5b..61f772c17a 100644
--- a/src/zeek-setup.cc
+++ b/src/zeek-setup.cc
@@ -116,9 +116,12 @@ std::vector<std::string> zeek_script_prefixes;
 zeek::detail::Stmt* stmts;
 zeek::EventRegistry* zeek::event_registry = nullptr;
 zeek::EventRegistry*& event_registry = zeek::event_registry;
-ProfileLogger* profiling_logger = nullptr;
-ProfileLogger* segment_logger = nullptr;
-SampleLogger* sample_logger = nullptr;
+zeek::detail::ProfileLogger* zeek::detail::profiling_logger = nullptr;
+zeek::detail::ProfileLogger*& profiling_logger = zeek::detail::profiling_logger;
+zeek::detail::ProfileLogger* zeek::detail::segment_logger = nullptr;
+zeek::detail::ProfileLogger*& segment_logger = zeek::detail::segment_logger;
+zeek::detail::SampleLogger* zeek::detail::sample_logger = nullptr;
+zeek::detail::SampleLogger*& sample_logger = zeek::detail::sample_logger;
 int signal_val = 0;
 extern char version[];
 const char* command_line_policy = nullptr;
@@ -236,8 +239,8 @@ void done_with_network()
 			true);
 		}
 
-	if ( profiling_logger )
-		profiling_logger->Log();
+	if ( zeek::detail::profiling_logger )
+		zeek::detail::profiling_logger->Log();
 
 	terminating = true;
 
@@ -287,14 +290,14 @@ void terminate_bro()
 	zeek::detail::timer_mgr->Expire();
 	zeek::event_mgr.Drain();
 
-	if ( profiling_logger )
+	if ( zeek::detail::profiling_logger )
 		{
 		// FIXME: There are some occasional crashes in the memory
 		// allocation code when killing Bro.  Disabling this for now.
 		if ( ! (signal_val == SIGTERM || signal_val == SIGINT) )
-			profiling_logger->Log();
+			zeek::detail::profiling_logger->Log();
 
-		delete profiling_logger;
+		delete zeek::detail::profiling_logger;
 		}
 
 	zeek::event_mgr.Drain();
@@ -794,11 +797,11 @@ zeek::detail::SetupResult zeek::detail::setup(int argc, char** argv,
 	if ( profiling_interval > 0 )
 		{
 		const auto& profiling_file = zeek::id::find_val("profiling_file");
-		profiling_logger = new ProfileLogger(profiling_file->AsFile(),
-			profiling_interval);
+		zeek::detail::profiling_logger = new ProfileLogger(profiling_file->AsFile(),
+		                                                   profiling_interval);
 
 		if ( segment_profiling )
-			segment_logger = profiling_logger;
+			zeek::detail::segment_logger = zeek::detail::profiling_logger;
 		}
 
 	if ( ! reading_live && ! reading_traces )
diff --git a/src/zeek.bif b/src/zeek.bif
index 4bd2e3f23e..9901f6f378 100644
--- a/src/zeek.bif
+++ b/src/zeek.bif
@@ -2030,8 +2030,8 @@ function record_fields%(rec: any%): record_field_table
 ##              get_timer_stats
 function do_profiling%(%) : any
 	%{
-	if ( profiling_logger )
-		profiling_logger->Log();
+	if ( zeek::detail::profiling_logger )
+		zeek::detail::profiling_logger->Log();
 
 	return nullptr;
 	%}