diff --git a/src/DNS_Mgr.cc b/src/DNS_Mgr.cc
index fa4f79f827..51a2fc448c 100644
--- a/src/DNS_Mgr.cc
+++ b/src/DNS_Mgr.cc
@@ -439,7 +439,7 @@ void DNS_Mgr::InitSource()
 
 	if ( nb_dns )
 		{
-		if ( ! iosource_mgr->RegisterFd(nb_dns_fd(nb_dns), this) )
+		if ( ! zeek::iosource_mgr->RegisterFd(nb_dns_fd(nb_dns), this) )
 			zeek::reporter->FatalError("Failed to register nb_dns file descriptor with iosource_mgr");
 		}
 	else
@@ -455,7 +455,7 @@ void DNS_Mgr::InitPostScript()
 	dm_rec = zeek::id::find_type<zeek::RecordType>("dns_mapping");
 
 	// Registering will call Init()
-	iosource_mgr->Register(this, true);
+	zeek::iosource_mgr->Register(this, true);
 
 	const char* cache_dir = dir ? dir : ".";
 	cache_name = new char[strlen(cache_dir) + 64];
@@ -1462,7 +1462,7 @@ void DNS_Mgr::GetStats(Stats* stats)
 void DNS_Mgr::Terminate()
 	{
 	if ( nb_dns )
-		iosource_mgr->UnregisterFd(nb_dns_fd(nb_dns), this);
+		zeek::iosource_mgr->UnregisterFd(nb_dns_fd(nb_dns), this);
 	}
 
 } // namespace zeek::detail
diff --git a/src/DNS_Mgr.h b/src/DNS_Mgr.h
index c61cb1fffb..3efb9bd648 100644
--- a/src/DNS_Mgr.h
+++ b/src/DNS_Mgr.h
@@ -47,7 +47,7 @@ enum DNS_MgrMode {
 // Number of seconds we'll wait for a reply.
 #define DNS_TIMEOUT 5
 
-class DNS_Mgr final : public iosource::IOSource {
+class DNS_Mgr final : public zeek::iosource::IOSource {
 public:
 	explicit DNS_Mgr(DNS_MgrMode mode);
 	~DNS_Mgr() override;
diff --git a/src/Event.cc b/src/Event.cc
index 4792f79326..caae05eb9b 100644
--- a/src/Event.cc
+++ b/src/Event.cc
@@ -223,7 +223,7 @@ void EventMgr::Process()
 	// If we don't have a source, or the source is closed, or we're
 	// reading live (which includes pseudo-realtime), advance the time
 	// here to the current time since otherwise it won't move forward.
-	iosource::PktSrc* pkt_src = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* pkt_src = zeek::iosource_mgr->GetPktSrc();
 	if ( ! pkt_src || ! pkt_src->IsOpen() || reading_live )
 		net_update_time(current_time());
 
@@ -233,16 +233,16 @@ void EventMgr::Process()
 	// to call Drain() as part of this method. It will get called at
 	// the end of net_run after all of the sources have been processed
 	// and had the opportunity to spawn new events. We could use
-	// iosource_mgr->Wakeup() instead of making EventMgr an IOSource,
+	// zeek::iosource_mgr->Wakeup() instead of making EventMgr an IOSource,
 	// but then we couldn't update the time above and nothing would
 	// drive it forward.
 	}
 
 void EventMgr::InitPostScript()
 	{
-	iosource_mgr->Register(this, true, false);
-	if ( ! iosource_mgr->RegisterFd(queue_flare.FD(), this) )
-		zeek::reporter->FatalError("Failed to register event manager FD with iosource_mgr");
+	zeek::iosource_mgr->Register(this, true, false);
+	if ( ! zeek::iosource_mgr->RegisterFd(queue_flare.FD(), this) )
+		zeek::reporter->FatalError("Failed to register event manager FD with zeek::iosource_mgr");
 	}
 
 } // namespace zeek
diff --git a/src/Net.cc b/src/Net.cc
index a9049088d4..ba8c79de74 100644
--- a/src/Net.cc
+++ b/src/Net.cc
@@ -42,7 +42,7 @@ extern "C" {
 extern int select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
 }
 
-iosource::PktDumper* pkt_dumper = nullptr;
+zeek::iosource::PktDumper* pkt_dumper = nullptr;
 
 bool reading_live = false;
 bool reading_traces = false;
@@ -60,8 +60,8 @@ bool is_parsing = false;
 const zeek::Packet *current_pkt = nullptr;
 int current_dispatched = 0;
 double current_timestamp = 0.0;
-iosource::PktSrc* current_pktsrc = nullptr;
-iosource::IOSource* current_iosrc = nullptr;
+zeek::iosource::PktSrc* current_pktsrc = nullptr;
+zeek::iosource::IOSource* current_iosrc = nullptr;
 
 std::list<ScannedFile> files_scanned;
 std::vector<std::string> sig_files;
@@ -110,7 +110,7 @@ RETSIGTYPE watchdog(int /* signo */)
 					// saving the packet which caused the
 					// watchdog to trigger may be helpful,
 					// so we'll save that one nevertheless.
-					pkt_dumper = iosource_mgr->OpenPktDumper("watchdog-pkt.pcap", false);
+					pkt_dumper = zeek::iosource_mgr->OpenPktDumper("watchdog-pkt.pcap", false);
 					if ( ! pkt_dumper || pkt_dumper->IsError() )
 						{
 						zeek::reporter->Error("watchdog: can't open watchdog-pkt.pcap for writing");
@@ -155,7 +155,7 @@ void net_init(const std::optional<std::string>& interface,
 		reading_live = pseudo_realtime > 0.0;
 		reading_traces = true;
 
-		iosource::PktSrc* ps = iosource_mgr->OpenPktSrc(*pcap_input_file, false);
+		zeek::iosource::PktSrc* ps = zeek::iosource_mgr->OpenPktSrc(*pcap_input_file, false);
 		assert(ps);
 
 		if ( ! ps->IsOpen() )
@@ -167,7 +167,7 @@ void net_init(const std::optional<std::string>& interface,
 		reading_live = true;
 		reading_traces = false;
 
-		iosource::PktSrc* ps = iosource_mgr->OpenPktSrc(*interface, true);
+		zeek::iosource::PktSrc* ps = zeek::iosource_mgr->OpenPktSrc(*interface, true);
 		assert(ps);
 
 		if ( ! ps->IsOpen() )
@@ -185,7 +185,7 @@ void net_init(const std::optional<std::string>& interface,
 	if ( pcap_output_file )
 		{
 		const char* writefile = pcap_output_file->data();
-		pkt_dumper = iosource_mgr->OpenPktDumper(writefile, false);
+		pkt_dumper = zeek::iosource_mgr->OpenPktDumper(writefile, false);
 		assert(pkt_dumper);
 
 		if ( ! pkt_dumper->IsOpen() )
@@ -210,7 +210,7 @@ void net_init(const std::optional<std::string>& interface,
 		}
 	}
 
-void expire_timers(iosource::PktSrc* src_ps)
+void expire_timers(zeek::iosource::PktSrc* src_ps)
 	{
 	zeek::detail::SegmentProfiler prof(zeek::detail::segment_logger, "expiring-timers");
 
@@ -219,7 +219,7 @@ void expire_timers(iosource::PktSrc* src_ps)
 			max_timer_expires - current_dispatched);
 	}
 
-void net_packet_dispatch(double t, const zeek::Packet* pkt, iosource::PktSrc* src_ps)
+void net_packet_dispatch(double t, const zeek::Packet* pkt, zeek::iosource::PktSrc* src_ps)
 	{
 	if ( ! bro_start_network_time )
 		{
@@ -278,13 +278,13 @@ void net_run()
 	{
 	set_processing_status("RUNNING", "net_run");
 
-	std::vector<iosource::IOSource*> ready;
-	ready.reserve(iosource_mgr->TotalSize());
+	std::vector<zeek::iosource::IOSource*> ready;
+	ready.reserve(zeek::iosource_mgr->TotalSize());
 
-	while ( iosource_mgr->Size() ||
+	while ( zeek::iosource_mgr->Size() ||
 		(zeek::BifConst::exit_only_after_terminate && ! terminating) )
 		{
-		iosource_mgr->FindReadySources(&ready);
+		zeek::iosource_mgr->FindReadySources(&ready);
 
 #ifdef DEBUG
 		static int loop_counter = 0;
@@ -347,7 +347,7 @@ void net_run()
 			{
 			auto have_active_packet_source = false;
 
-			iosource::PktSrc* ps = iosource_mgr->GetPktSrc();
+			zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc();
 			if ( ps && ps->IsOpen() )
 				have_active_packet_source = true;
 
@@ -366,10 +366,10 @@ void net_run()
 
 void net_get_final_stats()
 	{
-	iosource::PktSrc* ps = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc();
 	if ( ps && ps->IsLive() )
 		{
-		iosource::PktSrc::Stats s;
+		zeek::iosource::PktSrc::Stats s;
 		ps->Statistics(&s);
 		double dropped_pct = s.dropped > 0.0 ? ((double)s.dropped / ((double)s.received + (double)s.dropped)) * 100.0 : 0.0;
 		zeek::reporter->Info("%" PRIu64 " packets received on interface %s, %" PRIu64 " (%.2f%%) dropped",
@@ -427,7 +427,7 @@ void net_continue_processing()
 	if ( _processing_suspended == 1 )
 		{
 		zeek::reporter->Info("processing continued");
-		if ( iosource::PktSrc* ps = iosource_mgr->GetPktSrc() )
+		if ( zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc() )
 			ps->ContinueAfterSuspend();
 		}
 
diff --git a/src/Net.h b/src/Net.h
index 6f7df6121b..5fd9fa5563 100644
--- a/src/Net.h
+++ b/src/Net.h
@@ -11,12 +11,9 @@
 #include <string>
 #include <optional>
 
-namespace iosource {
-	class IOSource;
-	class PktSrc;
-	class PktDumper;
-	}
-
+ZEEK_FORWARD_DECLARE_NAMESPACED(IOSource, zeek, iosource);
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktSrc, zeek, iosource);
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktDumper, zeek, iosource);
 ZEEK_FORWARD_DECLARE_NAMESPACED(Packet, zeek);
 
 extern void net_init(const std::optional<std::string>& interfaces,
@@ -29,8 +26,8 @@ extern void net_finish(int drain_events);
 extern void net_delete();	// Reclaim all memory, etc.
 extern void net_update_time(double new_network_time);
 extern void net_packet_dispatch(double t, const zeek::Packet* pkt,
-			iosource::PktSrc* src_ps);
-extern void expire_timers(iosource::PktSrc* src_ps = nullptr);
+                                zeek::iosource::PktSrc* src_ps);
+extern void expire_timers(zeek::iosource::PktSrc* src_ps = nullptr);
 extern void zeek_terminate_loop(const char* reason);
 
 // Functions to temporarily suspend processing of live input (network packets
@@ -82,10 +79,10 @@ extern bool is_parsing;
 extern const zeek::Packet* current_pkt;
 extern int current_dispatched;
 extern double current_timestamp;
-extern iosource::PktSrc* current_pktsrc;
-extern iosource::IOSource* current_iosrc;
+extern zeek::iosource::PktSrc* current_pktsrc;
+extern zeek::iosource::IOSource* current_iosrc;
 
-extern iosource::PktDumper* pkt_dumper;	// where to save packets
+extern zeek::iosource::PktDumper* pkt_dumper;	// where to save packets
 
 // Script file we have already scanned (or are in the process of scanning).
 // They are identified by normalized realpath.
diff --git a/src/Timer.cc b/src/Timer.cc
index 0bca3ff670..69b57fef66 100644
--- a/src/Timer.cc
+++ b/src/Timer.cc
@@ -69,8 +69,8 @@ TimerMgr::TimerMgr()
 	num_expired = 0;
 	last_advance = last_timestamp = 0;
 
-	if ( iosource_mgr )
-		iosource_mgr->Register(this, true);
+	if ( zeek::iosource_mgr )
+		zeek::iosource_mgr->Register(this, true);
 	}
 
 TimerMgr::~TimerMgr()
@@ -95,7 +95,7 @@ void TimerMgr::Process()
 	// If we don't have a source, or the source is closed, or we're reading live (which includes
 	// pseudo-realtime), advance the timer here to the current time since otherwise it won't
 	// move forward and the timers won't fire correctly.
-	iosource::PktSrc* pkt_src = iosource_mgr->GetPktSrc();
+	iosource::PktSrc* pkt_src = zeek::iosource_mgr->GetPktSrc();
 	if ( ! pkt_src || ! pkt_src->IsOpen() || reading_live || net_is_processing_suspended() )
 		net_update_time(current_time());
 
@@ -106,8 +106,8 @@ void TimerMgr::Process()
 
 void TimerMgr::InitPostScript()
 	{
-	if ( iosource_mgr )
-		iosource_mgr->Register(this, true);
+	if ( zeek::iosource_mgr )
+		zeek::iosource_mgr->Register(this, true);
 	}
 
 PQ_TimerMgr::PQ_TimerMgr() : TimerMgr()
diff --git a/src/Trigger.cc b/src/Trigger.cc
index 8998239c0b..1af5b3b5a5 100644
--- a/src/Trigger.cc
+++ b/src/Trigger.cc
@@ -492,10 +492,10 @@ const char* Trigger::Name() const
 
 
 
-Manager::Manager() : IOSource()
+Manager::Manager() : zeek::iosource::IOSource()
 	{
 	pending = new TriggerList();
-	iosource_mgr->Register(this, true);
+	zeek::iosource_mgr->Register(this, true);
 	}
 
 Manager::~Manager()
@@ -540,7 +540,7 @@ void Manager::Queue(Trigger* trigger)
 		Ref(trigger);
 		pending->push_back(trigger);
 		total_triggers++;
-		iosource_mgr->Wakeup(Tag());
+		zeek::iosource_mgr->Wakeup(Tag());
 		}
 	}
 
diff --git a/src/Trigger.h b/src/Trigger.h
index 19ead2909e..d10da33292 100644
--- a/src/Trigger.h
+++ b/src/Trigger.h
@@ -117,7 +117,7 @@ private:
 
 using TriggerPtr = zeek::IntrusivePtr<Trigger>;
 
-class Manager final : public iosource::IOSource {
+class Manager final : public zeek::iosource::IOSource {
 public:
 
 	Manager();
@@ -143,7 +143,7 @@ private:
 	unsigned long total_triggers = 0;
 	};
 
-}
+} // namespace zeek::detail::trigger
 
 namespace trigger {
 	using Trigger [[deprecated("Remove in v4.1. Use zeek::detail::trigger::Trigger instead")]] = zeek::detail::trigger::Trigger;
diff --git a/src/broker/Manager.cc b/src/broker/Manager.cc
index 9cbbc51d1f..1b23deb7d4 100644
--- a/src/broker/Manager.cc
+++ b/src/broker/Manager.cc
@@ -163,7 +163,7 @@ void Manager::InitPostScript()
 	vector_of_data_type = zeek::make_intrusive<zeek::VectorType>(zeek::id::find_type("Broker::Data"));
 
 	// Register as a "dont-count" source first, we may change that later.
-	iosource_mgr->Register(this, true);
+	zeek::iosource_mgr->Register(this, true);
 
 	broker::broker_options options;
 	options.disable_ssl = get_option("Broker::disable_ssl")->AsBool();
@@ -210,9 +210,9 @@ void Manager::InitPostScript()
 	auto cqs = get_option("Broker::congestion_queue_size")->AsCount();
 	bstate = std::make_shared<BrokerState>(std::move(config), cqs);
 
-	if ( ! iosource_mgr->RegisterFd(bstate->subscriber.fd(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(bstate->subscriber.fd(), this) )
 		zeek::reporter->FatalError("Failed to register broker subscriber with iosource_mgr");
-	if ( ! iosource_mgr->RegisterFd(bstate->status_subscriber.fd(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(bstate->status_subscriber.fd(), this) )
 		zeek::reporter->FatalError("Failed to register broker status subscriber with iosource_mgr");
 
 	bstate->subscriber.add_topic(broker::topics::store_events, true);
@@ -268,8 +268,8 @@ void Manager::Terminate()
 	{
 	FlushLogBuffers();
 
-	iosource_mgr->UnregisterFd(bstate->subscriber.fd(), this);
-	iosource_mgr->UnregisterFd(bstate->status_subscriber.fd(), this);
+	zeek::iosource_mgr->UnregisterFd(bstate->subscriber.fd(), this);
+	zeek::iosource_mgr->UnregisterFd(bstate->status_subscriber.fd(), this);
 
 	vector<string> stores_to_close;
 
@@ -353,7 +353,7 @@ uint16_t Manager::Listen(const string& addr, uint16_t port)
 		      addr.empty() ? "INADDR_ANY" : addr.c_str(), port);
 
 	// Register as a "does-count" source now.
-	iosource_mgr->Register(this, false);
+	zeek::iosource_mgr->Register(this, false);
 
 	DBG_LOG(zeek::DBG_BROKER, "Listening on %s:%" PRIu16,
 		addr.empty() ? "INADDR_ANY" : addr.c_str(), port);
@@ -385,7 +385,7 @@ void Manager::Peer(const string& addr, uint16_t port, double retry)
 
 	if ( counts_as_iosource )
 		// Register as a "does-count" source now.
-		iosource_mgr->Register(this, false);
+		zeek::iosource_mgr->Register(this, false);
 	}
 
 void Manager::Unpeer(const string& addr, uint16_t port)
@@ -1598,7 +1598,7 @@ StoreHandleVal* Manager::MakeMaster(const string& name, broker::backend type,
 	Ref(handle);
 
 	data_stores.emplace(name, handle);
-	iosource_mgr->RegisterFd(handle->proxy.mailbox().descriptor(), this);
+	zeek::iosource_mgr->RegisterFd(handle->proxy.mailbox().descriptor(), this);
 	PrepareForwarding(name);
 
 	if ( ! bstate->endpoint.use_real_time() )
@@ -1695,7 +1695,7 @@ StoreHandleVal* Manager::MakeClone(const string& name, double resync_interval,
 	Ref(handle);
 
 	data_stores.emplace(name, handle);
-	iosource_mgr->RegisterFd(handle->proxy.mailbox().descriptor(), this);
+	zeek::iosource_mgr->RegisterFd(handle->proxy.mailbox().descriptor(), this);
 	PrepareForwarding(name);
 	return handle;
 	}
@@ -1714,7 +1714,7 @@ bool Manager::CloseStore(const string& name)
 	if ( s == data_stores.end() )
 		return false;
 
-	iosource_mgr->UnregisterFd(s->second->proxy.mailbox().descriptor(), this);
+	zeek::iosource_mgr->UnregisterFd(s->second->proxy.mailbox().descriptor(), this);
 
 	for ( auto i = pending_queries.begin(); i != pending_queries.end(); )
 		if ( i->second->Store().name() == name )
diff --git a/src/broker/Manager.h b/src/broker/Manager.h
index d8a461b625..eb8dd00957 100644
--- a/src/broker/Manager.h
+++ b/src/broker/Manager.h
@@ -66,7 +66,7 @@ struct Stats {
  * Manages various forms of communication between peer Bro processes
  * or other external applications via use of the Broker messaging library.
  */
-class Manager : public iosource::IOSource {
+class Manager : public zeek::iosource::IOSource {
 public:
     static const broker::endpoint_info NoPeer;
 
diff --git a/src/iosource/BPF_Program.cc b/src/iosource/BPF_Program.cc
index 35724ea42a..993b95ed6d 100644
--- a/src/iosource/BPF_Program.cc
+++ b/src/iosource/BPF_Program.cc
@@ -59,7 +59,7 @@ int pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
 }
 #endif
 
-namespace zeek::detail {
+namespace zeek::iosource::detail {
 
 // Simple heuristic to identify filters that always match, so that we can
 // skip the filtering in that case. "ip or not ip" is Bro's default filter.
@@ -161,4 +161,4 @@ void BPF_Program::FreeCode()
 		}
 	}
 
-} // namespace zeek::detail
+} // namespace zeek::iosource::detail
diff --git a/src/iosource/BPF_Program.h b/src/iosource/BPF_Program.h
index e8ea2b3dd2..f19909f1ad 100644
--- a/src/iosource/BPF_Program.h
+++ b/src/iosource/BPF_Program.h
@@ -8,7 +8,7 @@ extern "C" {
 
 #include <stdint.h>
 
-namespace zeek::detail {
+namespace zeek::iosource::detail {
 
 // BPF_Programs are an abstraction around struct bpf_program,
 // to create a clean facility for creating, compiling, and
@@ -56,6 +56,6 @@ protected:
 	struct bpf_program m_program;
 };
 
-} // namespace zeek::detail
+} // namespace zeek::iosource::detail
 
-using BPF_Program [[deprecated("Remove in v4.1. Use zeek::detail::BPF_Program.")]] = zeek::detail::BPF_Program;
+using BPF_Program [[deprecated("Remove in v4.1. Use zeek::iosource::detail::BPF_Program.")]] = zeek::iosource::detail::BPF_Program;
diff --git a/src/iosource/Component.cc b/src/iosource/Component.cc
index b7ad278e68..c7a1af6917 100644
--- a/src/iosource/Component.cc
+++ b/src/iosource/Component.cc
@@ -5,7 +5,7 @@
 #include "Desc.h"
 #include "Reporter.h"
 
-using namespace iosource;
+namespace zeek::iosource {
 
 Component::Component(const std::string& name)
 	: zeek::plugin::Component(zeek::plugin::component::IOSOURCE, name)
@@ -163,3 +163,5 @@ void PktDumperComponent::DoDescribe(zeek::ODesc* d) const
 	d->Add(": ");
 	d->Add(prefs);
 	}
+
+} // namespace zeek::iosource
diff --git a/src/iosource/Component.h b/src/iosource/Component.h
index 0916709b28..d07c3a3811 100644
--- a/src/iosource/Component.h
+++ b/src/iosource/Component.h
@@ -2,16 +2,16 @@
 
 #pragma once
 
-#include "plugin/Component.h"
-
 #include <string>
 #include <vector>
 
-namespace iosource {
+#include "plugin/Component.h"
 
-class IOSource;
-class PktSrc;
-class PktDumper;
+ZEEK_FORWARD_DECLARE_NAMESPACED(IOSource, zeek, iosource);
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktSrc, zeek, iosource);
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktDumper, zeek, iosource);
+
+namespace zeek::iosource {
 
 /**
  * Component description for plugins providing IOSources.
@@ -49,7 +49,7 @@ protected:
 /**
  * Component description for plugins providing a PktSrc for packet input.
  */
-class PktSrcComponent : public iosource::Component {
+class PktSrcComponent : public zeek::iosource::Component {
 public:
 	/**
 	 * Type of input a packet source supports.
@@ -167,4 +167,12 @@ private:
 	factory_callback factory;
 };
 
-}
+} // namespace zeek::iosource
+
+namespace iosource {
+
+	using Component [[deprecated("Remove in v4.1. Use zeek::iosource::Component.")]] = zeek::iosource::Component;
+	using PktSrcComponent [[deprecated("Remove in v4.1. Use zeek::iosource::PktSrcComponent.")]] = zeek::iosource::PktSrcComponent;
+	using PktDumperComponent [[deprecated("Remove in v4.1. Use zeek::iosource::PktDumperComponent.")]] = zeek::iosource::PktDumperComponent;
+
+} // namespace iosource
diff --git a/src/iosource/IOSource.h b/src/iosource/IOSource.h
index ea218a675b..3d63bb3c7a 100644
--- a/src/iosource/IOSource.h
+++ b/src/iosource/IOSource.h
@@ -2,7 +2,7 @@
 
 #pragma once
 
-namespace iosource {
+namespace zeek::iosource {
 
 /**
  * Interface class for components providing/consuming data inside Bro's main
@@ -86,4 +86,8 @@ private:
 	bool closed;
 };
 
+} // namespace zeek::iosource
+
+namespace iosource {
+	using IOSource [[deprecated("Remove in v4.1. Use zeek::iosource::IOSource.")]] = zeek::iosource::IOSource;
 }
diff --git a/src/iosource/Manager.cc b/src/iosource/Manager.cc
index de07a87bfa..196146dcd1 100644
--- a/src/iosource/Manager.cc
+++ b/src/iosource/Manager.cc
@@ -20,7 +20,7 @@
 
 #define DEFAULT_PREFIX "pcap"
 
-using namespace iosource;
+namespace zeek::iosource {
 
 Manager::WakeupHandler::WakeupHandler()
 	{
@@ -417,3 +417,5 @@ PktDumper* Manager::OpenPktDumper(const std::string& path, bool append)
 
 	return pd;
 	}
+
+} // namespace zeek::iosource
diff --git a/src/iosource/Manager.h b/src/iosource/Manager.h
index bd875f5fae..8c59478a8e 100644
--- a/src/iosource/Manager.h
+++ b/src/iosource/Manager.h
@@ -14,10 +14,11 @@
 struct timespec;
 struct kevent;
 
-namespace iosource {
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktSrc, zeek, iosource);
+ZEEK_FORWARD_DECLARE_NAMESPACED(PktDumper, zeek, iosource);
 
-class PktSrc;
-class PktDumper;
+namespace zeek {
+namespace iosource {
 
 /**
  * Manager class for IO sources. This handles all of the polling of sources
@@ -209,6 +210,14 @@ private:
 	std::vector<struct kevent> events;
 };
 
-}
+} // namespace iosource
 
 extern iosource::Manager* iosource_mgr;
+
+} // namespace zeek
+
+extern zeek::iosource::Manager*& iosource_mgr [[deprecated("Remove in v4.1. Use zeek::iosource_mgr.")]];
+
+namespace iosource {
+	using Manager [[deprecated("Remove in v4.1. Use zeek::iosource::Manager.")]] = zeek::iosource::Manager;
+}
diff --git a/src/iosource/PktDumper.cc b/src/iosource/PktDumper.cc
index 1ada2a3021..0ca6511df9 100644
--- a/src/iosource/PktDumper.cc
+++ b/src/iosource/PktDumper.cc
@@ -6,7 +6,7 @@
 #include "PktDumper.h"
 #include "DebugLogger.h"
 
-using namespace iosource;
+namespace zeek::iosource {
 
 PktDumper::PktDumper()
 	{
@@ -80,3 +80,5 @@ void PktDumper::Error(const std::string& msg)
 		IsOpen() ? props.path.c_str() : "<not open>",
 		msg.c_str());
 	}
+
+} // namespace zeek::iosource
diff --git a/src/iosource/PktDumper.h b/src/iosource/PktDumper.h
index f474a7e8a3..ac7e7bc850 100644
--- a/src/iosource/PktDumper.h
+++ b/src/iosource/PktDumper.h
@@ -7,7 +7,7 @@
 
 ZEEK_FORWARD_DECLARE_NAMESPACED(Packet, zeek);
 
-namespace iosource {
+namespace zeek::iosource {
 
 /**
  * Base class for packet dumpers.
@@ -139,4 +139,8 @@ private:
 	std::string errmsg;
 };
 
+} // namespace zeek::iosource
+
+namespace iosource {
+	using PktDumper [[deprecated("Remove in v4.1. Use zeek::iosource::PktDumper.")]] = zeek::iosource::PktDumper;
 }
diff --git a/src/iosource/PktSrc.cc b/src/iosource/PktSrc.cc
index 3db44cc9ae..8e3c2dcace 100644
--- a/src/iosource/PktSrc.cc
+++ b/src/iosource/PktSrc.cc
@@ -15,7 +15,7 @@
 
 #include "pcap/pcap.bif.h"
 
-using namespace iosource;
+namespace zeek::iosource {
 
 PktSrc::Properties::Properties()
 	{
@@ -269,7 +269,7 @@ bool PktSrc::PrecompileBPFFilter(int index, const std::string& filter)
 	char errbuf[PCAP_ERRBUF_SIZE];
 
 	// Compile filter.
-	auto* code = new zeek::detail::BPF_Program();
+	auto* code = new zeek::iosource::detail::BPF_Program();
 
 	if ( ! code->Compile(zeek::BifConst::Pcap::snaplen, LinkType(), filter.c_str(), Netmask(), errbuf, sizeof(errbuf)) )
 		{
@@ -296,7 +296,7 @@ bool PktSrc::PrecompileBPFFilter(int index, const std::string& filter)
 	return true;
 	}
 
-zeek::detail::BPF_Program* PktSrc::GetBPFFilter(int index)
+zeek::iosource::detail::BPF_Program* PktSrc::GetBPFFilter(int index)
 	{
 	if ( index < 0 )
 		return nullptr;
@@ -306,7 +306,7 @@ zeek::detail::BPF_Program* PktSrc::GetBPFFilter(int index)
 
 bool PktSrc::ApplyBPFFilter(int index, const struct pcap_pkthdr *hdr, const u_char *pkt)
 	{
-	zeek::detail::BPF_Program* code = GetBPFFilter(index);
+	zeek::iosource::detail::BPF_Program* code = GetBPFFilter(index);
 
 	if ( ! code )
 		{
@@ -356,3 +356,5 @@ double PktSrc::GetNextTimeout()
 	double ct = (current_time(true) - first_wallclock) * pseudo_realtime;
 	return std::max(0.0, pseudo_time - ct);
 	}
+
+} // namespace zeek::iosource
diff --git a/src/iosource/PktSrc.h b/src/iosource/PktSrc.h
index 2dd340cf4a..9c8178076f 100644
--- a/src/iosource/PktSrc.h
+++ b/src/iosource/PktSrc.h
@@ -10,9 +10,9 @@
 #include <sys/types.h> // for u_char
 
 struct pcap_pkthdr;
-ZEEK_FORWARD_DECLARE_NAMESPACED(BPF_Program, zeek::detail);
+ZEEK_FORWARD_DECLARE_NAMESPACED(BPF_Program, zeek::iosource::detail);
 
-namespace iosource {
+namespace zeek::iosource {
 
 /**
  * Base class for packet sources.
@@ -136,7 +136,7 @@ public:
 	 * @return The BPF filter associated, or null if none has been
 	 * (successfully) compiled.
 	 */
-	zeek::detail::BPF_Program* GetBPFFilter(int index);
+	zeek::iosource::detail::BPF_Program* GetBPFFilter(int index);
 
 	/**
 	 * Applies a precompiled BPF filter to a packet. This will close the
@@ -368,7 +368,7 @@ private:
 	zeek::Packet current_packet;
 
 	// For BPF filtering support.
-	std::vector<zeek::detail::BPF_Program *> filters;
+	std::vector<zeek::iosource::detail::BPF_Program *> filters;
 
 	// Only set in pseudo-realtime mode.
 	double first_timestamp;
@@ -380,4 +380,8 @@ private:
 	std::string errbuf;
 };
 
+} // namespace zeek::iosource
+
+namespace iosource {
+	using PktSrc [[deprecated("Remove in v4.1. Use zeek::iosource::PktSrc.")]] = zeek::iosource::PktSrc;
 }
diff --git a/src/iosource/pcap/Dumper.cc b/src/iosource/pcap/Dumper.cc
index 83072a4f49..6915c72b59 100644
--- a/src/iosource/pcap/Dumper.cc
+++ b/src/iosource/pcap/Dumper.cc
@@ -9,7 +9,7 @@
 
 #include "pcap.bif.h"
 
-using namespace iosource::pcap;
+namespace zeek::iosource::pcap {
 
 PcapDumper::PcapDumper(const std::string& path, bool arg_append)
 	{
@@ -117,3 +117,5 @@ iosource::PktDumper* PcapDumper::Instantiate(const std::string& path, bool appen
 	{
 	return new PcapDumper(path, append);
 	}
+
+} // namespace zeek::iosource::pcap
diff --git a/src/iosource/pcap/Dumper.h b/src/iosource/pcap/Dumper.h
index 131c675983..a2caba94f2 100644
--- a/src/iosource/pcap/Dumper.h
+++ b/src/iosource/pcap/Dumper.h
@@ -8,8 +8,7 @@ extern "C" {
 
 #include "../PktDumper.h"
 
-namespace iosource {
-namespace pcap {
+namespace zeek::iosource::pcap {
 
 class PcapDumper : public PktDumper {
 public:
@@ -32,5 +31,8 @@ private:
 	pcap_t* pd;
 };
 
-}
+} // namespace zeek::iosource::pcap
+
+namespace iosource::pcap {
+	using PcapDumper [[deprecated("Remove in v4.1. Use zeek::iosource::pcap::PcapDumper.")]] = zeek::iosource::pcap::PcapDumper;
 }
diff --git a/src/iosource/pcap/Plugin.cc b/src/iosource/pcap/Plugin.cc
index 388645a598..5250b032b3 100644
--- a/src/iosource/pcap/Plugin.cc
+++ b/src/iosource/pcap/Plugin.cc
@@ -5,15 +5,17 @@
 #include "plugin/Plugin.h"
 #include "iosource/Component.h"
 
-namespace plugin {
-namespace Zeek_Pcap {
+namespace zeek::plugin::Zeek_Pcap {
 
 class Plugin : public zeek::plugin::Plugin {
 public:
 	zeek::plugin::Configuration Configure() override
 		{
-		AddComponent(new ::iosource::PktSrcComponent("PcapReader", "pcap", ::iosource::PktSrcComponent::BOTH, ::iosource::pcap::PcapSource::Instantiate));
-		AddComponent(new ::iosource::PktDumperComponent("PcapWriter", "pcap", ::iosource::pcap::PcapDumper::Instantiate));
+		AddComponent(new zeek::iosource::PktSrcComponent(
+			             "PcapReader", "pcap", zeek::iosource::PktSrcComponent::BOTH,
+			             zeek::iosource::pcap::PcapSource::Instantiate));
+		AddComponent(new zeek::iosource::PktDumperComponent(
+			             "PcapWriter", "pcap", zeek::iosource::pcap::PcapDumper::Instantiate));
 
 		zeek::plugin::Configuration config;
 		config.name = "Zeek::Pcap";
@@ -22,5 +24,4 @@ public:
 		}
 } plugin;
 
-}
-}
+} // namespace zeek::plugin::Zeek_Pcap
diff --git a/src/iosource/pcap/Source.cc b/src/iosource/pcap/Source.cc
index ae0be127b2..4bda7476a0 100644
--- a/src/iosource/pcap/Source.cc
+++ b/src/iosource/pcap/Source.cc
@@ -14,7 +14,7 @@
 #include <pcap-int.h>
 #endif
 
-using namespace iosource::pcap;
+namespace zeek::iosource::pcap {
 
 PcapSource::~PcapSource()
 	{
@@ -258,7 +258,7 @@ bool PcapSource::SetFilter(int index)
 
 	char errbuf[PCAP_ERRBUF_SIZE];
 
-	zeek::detail::BPF_Program* code = GetBPFFilter(index);
+	zeek::iosource::detail::BPF_Program* code = GetBPFFilter(index);
 
 	if ( ! code )
 		{
@@ -342,3 +342,5 @@ iosource::PktSrc* PcapSource::Instantiate(const std::string& path, bool is_live)
 	{
 	return new PcapSource(path, is_live);
 	}
+
+} // namespace zeek::iosource::pcap
diff --git a/src/iosource/pcap/Source.h b/src/iosource/pcap/Source.h
index 78f57afe39..d3f8ddae5e 100644
--- a/src/iosource/pcap/Source.h
+++ b/src/iosource/pcap/Source.h
@@ -10,10 +10,9 @@ extern "C" {
 
 #include <sys/types.h> // for u_char
 
-namespace iosource {
-namespace pcap {
+namespace zeek::iosource::pcap {
 
-class PcapSource : public iosource::PktSrc {
+class PcapSource : public zeek::iosource::PktSrc {
 public:
 	PcapSource(const std::string& path, bool is_live);
 	~PcapSource() override;
@@ -41,5 +40,8 @@ private:
 	pcap_t *pd;
 };
 
-}
+} // namespace zeek::iosource::pcap
+
+namespace iosource::pcap {
+	using PcapSource [[deprecated("Remove in v4.1. Use zeek::iosource::pcap::PcapSource.")]] = zeek::iosource::pcap::PcapSource;
 }
diff --git a/src/iosource/pcap/pcap.bif b/src/iosource/pcap/pcap.bif
index 5fe6b92233..8058e6743e 100644
--- a/src/iosource/pcap/pcap.bif
+++ b/src/iosource/pcap/pcap.bif
@@ -39,7 +39,7 @@ function precompile_pcap_filter%(id: PcapFilterID, s: string%): bool
 
 	bool success = true;
 
-	iosource::PktSrc* ps = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc();
 	if ( ps && ! ps->PrecompileFilter(id->ForceAsInt(), s->CheckString()) )
 		success = false;
 
@@ -68,7 +68,7 @@ function Pcap::install_pcap_filter%(id: PcapFilterID%): bool
 	%{
 	bool success = true;
 
-	iosource::PktSrc* ps = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc();
 	if ( ps && ! ps->SetFilter(id->ForceAsInt()) )
 		success = false;
 
@@ -91,7 +91,7 @@ function Pcap::install_pcap_filter%(id: PcapFilterID%): bool
 ##              uninstall_dst_net_filter
 function error%(%): string
 	%{
-	iosource::PktSrc* ps = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc();
 	if ( ps )
 		{
 		const char* err = ps->ErrorMsg();
diff --git a/src/main.cc b/src/main.cc
index cdabc30176..56c5b5401f 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -16,7 +16,7 @@ int main(int argc, char** argv)
 		return setup_result.code;
 
 	auto& options = setup_result.options;
-	auto do_net_run = iosource_mgr->Size() > 0 ||
+	auto do_net_run = zeek::iosource_mgr->Size() > 0 ||
 	                  have_pending_timers ||
 	                  zeek::BifConst::exit_only_after_terminate;
 
diff --git a/src/stats.bif b/src/stats.bif
index 53c64fcf09..7042d86d3f 100644
--- a/src/stats.bif
+++ b/src/stats.bif
@@ -44,9 +44,9 @@ function get_net_stats%(%): NetStats
 	uint64_t link = 0;
 	uint64_t bytes_recv = 0;
 
-	if ( iosource::PktSrc* ps = iosource_mgr->GetPktSrc() )
+	if ( zeek::iosource::PktSrc* ps = zeek::iosource_mgr->GetPktSrc() )
 		{
-		struct iosource::PktSrc::Stats stat;
+		struct zeek::iosource::PktSrc::Stats stat;
 		ps->Statistics(&stat);
 		recv += stat.received;
 		drop += stat.dropped;
diff --git a/src/supervisor/Supervisor.cc b/src/supervisor/Supervisor.cc
index c7e440ffd4..6c67856cf9 100644
--- a/src/supervisor/Supervisor.cc
+++ b/src/supervisor/Supervisor.cc
@@ -255,8 +255,8 @@ Supervisor::~Supervisor()
 		return;
 		}
 
-	iosource_mgr->UnregisterFd(signal_flare.FD(), this);
-	iosource_mgr->UnregisterFd(stem_pipe->InFD(), this);
+	zeek::iosource_mgr->UnregisterFd(signal_flare.FD(), this);
+	zeek::iosource_mgr->UnregisterFd(stem_pipe->InFD(), this);
 
 	DBG_LOG(zeek::DBG_SUPERVISOR, "shutdown, killing stem process %d", stem_pid);
 
@@ -449,11 +449,11 @@ void Supervisor::HandleChildSignal()
 		}
 	else
 		{
-		if ( ! iosource_mgr->UnregisterFd(stem_stdout.pipe->ReadFD(), this) )
+		if ( ! zeek::iosource_mgr->UnregisterFd(stem_stdout.pipe->ReadFD(), this) )
 			reporter->FatalError("Revived supervisor stem failed to unregister "
 								 "redirected stdout pipe");
 
-		if ( ! iosource_mgr->UnregisterFd(stem_stderr.pipe->ReadFD(), this) )
+		if ( ! zeek::iosource_mgr->UnregisterFd(stem_stderr.pipe->ReadFD(), this) )
 			reporter->FatalError("Revived supervisor stem failed to unregister "
 								 "redirected stderr pipe");
 
@@ -462,11 +462,11 @@ void Supervisor::HandleChildSignal()
 		stem_stdout.pipe = std::move(fork_res.stdout_pipe);
 		stem_stderr.pipe = std::move(fork_res.stderr_pipe);
 
-		if ( ! iosource_mgr->RegisterFd(stem_stdout.pipe->ReadFD(), this) )
+		if ( ! zeek::iosource_mgr->RegisterFd(stem_stdout.pipe->ReadFD(), this) )
 			reporter->FatalError("Revived supervisor stem failed to register "
 								 "redirected stdout pipe");
 
-		if ( ! iosource_mgr->RegisterFd(stem_stderr.pipe->ReadFD(), this) )
+		if ( ! zeek::iosource_mgr->RegisterFd(stem_stderr.pipe->ReadFD(), this) )
 			reporter->FatalError("Revived supervisor stem failed to register "
 								 "redirected stderr pipe");
 		}
@@ -494,18 +494,18 @@ void Supervisor::InitPostScript()
 	stem_stdout.hook = id::find_func("Supervisor::stdout_hook");
 	stem_stderr.hook = id::find_func("Supervisor::stderr_hook");
 
-	iosource_mgr->Register(this);
+	zeek::iosource_mgr->Register(this);
 
-	if ( ! iosource_mgr->RegisterFd(signal_flare.FD(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(signal_flare.FD(), this) )
 		reporter->FatalError("Supervisor stem failed to register signal_flare");
 
-	if ( ! iosource_mgr->RegisterFd(stem_pipe->InFD(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(stem_pipe->InFD(), this) )
 		reporter->FatalError("Supervisor stem failed to register stem_pipe");
 
-	if ( ! iosource_mgr->RegisterFd(stem_stdout.pipe->ReadFD(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(stem_stdout.pipe->ReadFD(), this) )
 		reporter->FatalError("Supervisor stem failed to register stdout pipe");
 
-	if ( ! iosource_mgr->RegisterFd(stem_stderr.pipe->ReadFD(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(stem_stderr.pipe->ReadFD(), this) )
 		reporter->FatalError("Supervisor stem failed to register stderr pipe");
 	}
 
diff --git a/src/threading/MsgThread.cc b/src/threading/MsgThread.cc
index ce1004b0f5..2c12dc3b05 100644
--- a/src/threading/MsgThread.cc
+++ b/src/threading/MsgThread.cc
@@ -206,7 +206,7 @@ MsgThread::MsgThread() : BasicThread(), queue_in(this, nullptr), queue_out(nullp
 	failed = false;
 	thread_mgr->AddMsgThread(this);
 
-	if ( ! iosource_mgr->RegisterFd(flare.FD(), this) )
+	if ( ! zeek::iosource_mgr->RegisterFd(flare.FD(), this) )
 		zeek::reporter->FatalError("Failed to register MsgThread fd with iosource_mgr");
 
 	SetClosed(false);
@@ -216,7 +216,7 @@ MsgThread::~MsgThread()
 	{
 	// Unregister this thread from the iosource manager so it doesn't wake
 	// up the main poll anymore.
-	iosource_mgr->UnregisterFd(flare.FD(), this);
+	zeek::iosource_mgr->UnregisterFd(flare.FD(), this);
 	}
 
 // Set by Bro's main signal handler.
diff --git a/src/threading/MsgThread.h b/src/threading/MsgThread.h
index 4eac9e1d36..f62abfea03 100644
--- a/src/threading/MsgThread.h
+++ b/src/threading/MsgThread.h
@@ -27,7 +27,7 @@ struct Field;
  * that happens, the thread stops accepting any new messages, finishes
  * processes all remaining ones still in the queue, and then exits.
  */
-class MsgThread : public BasicThread, public iosource::IOSource
+class MsgThread : public BasicThread, public zeek::iosource::IOSource
 {
 public:
 	/**
diff --git a/src/util.cc b/src/util.cc
index 417aed4d2b..c8ef5d2883 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -2025,11 +2025,11 @@ double current_time(bool real)
 
 	double t = double(tv.tv_sec) + double(tv.tv_usec) / 1e6;
 
-	if ( ! pseudo_realtime || real || ! iosource_mgr || ! iosource_mgr->GetPktSrc() )
+	if ( ! pseudo_realtime || real || ! zeek::iosource_mgr || ! zeek::iosource_mgr->GetPktSrc() )
 		return t;
 
 	// This obviously only works for a single source ...
-	iosource::PktSrc* src = iosource_mgr->GetPktSrc();
+	zeek::iosource::PktSrc* src = zeek::iosource_mgr->GetPktSrc();
 
 	if ( net_is_processing_suspended() )
 		return src->CurrentPacketTimestamp();
diff --git a/src/zeek-setup.cc b/src/zeek-setup.cc
index 10cb67ef02..b20cc25688 100644
--- a/src/zeek-setup.cc
+++ b/src/zeek-setup.cc
@@ -110,7 +110,8 @@ zeek::input::Manager*& input_mgr = zeek::input_mgr;
 zeek::file_analysis::Manager* zeek::file_mgr = nullptr;
 zeek::file_analysis::Manager*& file_mgr = zeek::file_mgr;
 zeekygen::Manager* zeekygen_mgr = nullptr;
-iosource::Manager* iosource_mgr = nullptr;
+zeek::iosource::Manager* zeek::iosource_mgr = nullptr;
+zeek::iosource::Manager*& iosource_mgr = zeek::iosource_mgr;
 bro_broker::Manager* broker_mgr = nullptr;
 zeek::Supervisor* zeek::supervisor_mgr = nullptr;
 zeek::detail::trigger::Manager* trigger_mgr = nullptr;
@@ -279,7 +280,7 @@ void terminate_bro()
 
 	terminating = true;
 
-	iosource_mgr->Wakeup("terminate_bro");
+	zeek::iosource_mgr->Wakeup("terminate_bro");
 
 	// File analysis termination may produce events, so do it early on in
 	// the termination process.
@@ -320,7 +321,7 @@ void terminate_bro()
 	delete zeek::analyzer_mgr;
 	delete zeek::file_mgr;
 	// broker_mgr, timer_mgr, and supervisor are deleted via iosource_mgr
-	delete iosource_mgr;
+	delete zeek::iosource_mgr;
 	delete zeek::event_registry;
 	delete zeek::log_mgr;
 	delete zeek::reporter;
@@ -359,7 +360,7 @@ RETSIGTYPE sig_handler(int signo)
 	signal_val = signo;
 
 	if ( ! terminating )
-		iosource_mgr->Wakeup("sig_handler");
+		zeek::iosource_mgr->Wakeup("sig_handler");
 
 	return RETSIGVAL;
 	}
@@ -579,7 +580,7 @@ zeek::detail::SetupResult zeek::detail::setup(int argc, char** argv,
 	// policy, but we can't parse policy without DNS resolution.
 	zeek::detail::dns_mgr->SetDir(".state");
 
-	iosource_mgr = new iosource::Manager();
+	zeek::iosource_mgr = new iosource::Manager();
 	event_registry = new EventRegistry();
 	zeek::analyzer_mgr = new analyzer::Manager();
 	zeek::log_mgr = new logging::Manager();
@@ -659,7 +660,7 @@ zeek::detail::SetupResult zeek::detail::setup(int argc, char** argv,
 	if ( zeek::reporter->Errors() > 0 )
 		exit(1);
 
-	iosource_mgr->InitPostScript();
+	zeek::iosource_mgr->InitPostScript();
 	zeek::log_mgr->InitPostScript();
 	zeek::plugin_mgr->InitPostScript();
 	zeekygen_mgr->InitPostScript();
diff --git a/src/zeek.bif b/src/zeek.bif
index 429b944ea3..42d0466976 100644
--- a/src/zeek.bif
+++ b/src/zeek.bif
@@ -33,7 +33,7 @@ using namespace std;
 
 zeek::TableType* var_sizes;
 
-static iosource::PktDumper* addl_pkt_dumper = 0;
+static zeek::iosource::PktDumper* addl_pkt_dumper = nullptr;
 
 bro_int_t parse_int(const char*& fmt)
 	{
@@ -1891,7 +1891,7 @@ function reading_traces%(%): bool
 function packet_source%(%): PacketSource
 	%{
 	static auto ps_type = zeek::id::find_type<zeek::RecordType>("PacketSource");
-	auto ps = iosource_mgr->GetPktSrc();
+	auto ps = zeek::iosource_mgr->GetPktSrc();
 	auto r = zeek::make_intrusive<zeek::RecordVal>(ps_type);
 
 	if ( ps )
@@ -3407,7 +3407,7 @@ function dump_current_packet%(file_name: string%) : bool
 		}
 
 	if ( ! addl_pkt_dumper )
-		addl_pkt_dumper = iosource_mgr->OpenPktDumper(file_name->CheckString(), true);
+		addl_pkt_dumper = zeek::iosource_mgr->OpenPktDumper(file_name->CheckString(), true);
 
 	if ( addl_pkt_dumper )
 		{
@@ -3490,7 +3490,7 @@ function dump_packet%(pkt: pcap_packet, file_name: string%) : bool
 		}
 
 	if ( ! addl_pkt_dumper )
-		addl_pkt_dumper = iosource_mgr->OpenPktDumper(file_name->CheckString(), true);
+		addl_pkt_dumper = zeek::iosource_mgr->OpenPktDumper(file_name->CheckString(), true);
 
 	if ( ! addl_pkt_dumper->IsError() )
 		{