diff --git a/src/Stats.cc b/src/Stats.cc
index 50f24dae5a..759f95972b 100644
--- a/src/Stats.cc
+++ b/src/Stats.cc
@@ -252,7 +252,7 @@ void ProfileLogger::Log()
 
 		for ( const auto& global : globals )
 			{
-			auto id = global.second;
+			auto& id = global.second;
 
 			// We don't show/count internal globals as they are always
 			// contained in some other global user-visible container.
diff --git a/src/Type.h b/src/Type.h
index bc35e752b6..c29f6fb32b 100644
--- a/src/Type.h
+++ b/src/Type.h
@@ -21,7 +21,6 @@ FORWARD_DECLARE_NAMESPACED(Expr, zeek::detail);
 FORWARD_DECLARE_NAMESPACED(ListExpr, zeek::detail);
 FORWARD_DECLARE_NAMESPACED(Attributes, zeek::detail);
 
-// BRO types.
 enum [[deprecated("Remove in v4.1. Use zeek::TypeTag instead.")]] TypeTag {
 	TYPE_VOID,      // 0
 	TYPE_BOOL,      // 1
@@ -977,17 +976,17 @@ inline bool EitherError(TypeTag t1, TypeTag t2) { return (IsErrorType(t1) || IsE
 // Returns the basic (non-parameterized) type with the given type.
 const IntrusivePtr<zeek::BroType>& base_type(zeek::TypeTag tag);
 
-// Returns the basic (non-parameterized) type with the given type.
-// The reference count of the type is not increased.
-[[deprecated("Remove in v4.1.  Use ::base_type() instead")]]
-inline zeek::BroType* base_type_no_ref(TypeTag tag)
-       { return base_type(tag).get(); }
-
 // Returns the basic error type.
 inline const IntrusivePtr<zeek::BroType>& error_type()       { return base_type(TYPE_ERROR); }
 
 } // namespace zeek
 
+// Returns the basic (non-parameterized) type with the given type.
+// The reference count of the type is not increased.
+[[deprecated("Remove in v4.1.  Use zeek::base_type() instead")]]
+inline zeek::BroType* base_type_no_ref(TypeTag tag)
+	{ return zeek::base_type(static_cast<zeek::TypeTag>(tag)).get(); }
+
 extern IntrusivePtr<zeek::OpaqueType> md5_type;
 extern IntrusivePtr<zeek::OpaqueType> sha1_type;
 extern IntrusivePtr<zeek::OpaqueType> sha256_type;
diff --git a/src/Val.h b/src/Val.h
index f7ea2e0cbb..1aebc0f887 100644
--- a/src/Val.h
+++ b/src/Val.h
@@ -125,7 +125,7 @@ public:
 		: val(d), type(zeek::base_type(t))
 		{}
 
-	[[deprecated("Remove in v4.1. Use version that takes zeek::TypeTag instead.")]]
+	[[deprecated("Remove in v4.1.  Use IntervalVal(), TimeVal(), or DoubleVal() constructors.")]]
 	Val(double d, ::TypeTag t) : Val(d, static_cast<zeek::TypeTag>(t))
 		{}
 
@@ -1004,7 +1004,7 @@ public:
 	notifier::Modifiable* Modifiable() override	{ return this; }
 
 	// Retrieves and saves all table state (key-value pairs) for
-	// tables whose index type depends on the given zeek::detail::RecordType.
+	// tables whose index type depends on the given zeek::RecordType.
 	static void SaveParseTimeTableState(zeek::RecordType* rt);
 
 	// Rebuilds all TableVals whose state was previously saved by
@@ -1013,7 +1013,7 @@ public:
 	static void RebuildParseTimeTables();
 
 	// Clears all state that was used to track TableVals that depending
-	// on zeek::detail::RecordTypes.
+	// on zeek::RecordTypes.
 	static void DoneParsing();
 
 protected:
diff --git a/src/input/readers/config/Config.cc b/src/input/readers/config/Config.cc
index e3199c78ba..56d93fcfb0 100644
--- a/src/input/readers/config/Config.cc
+++ b/src/input/readers/config/Config.cc
@@ -31,7 +31,7 @@ Config::Config(ReaderFrontend *frontend) : ReaderBackend(frontend)
 
 	for ( const auto& entry : globals )
 		{
-		auto id = entry.second;
+		auto& id = entry.second;
 		if ( ! id->IsOption() )
 			continue;
 
diff --git a/src/plugin/Plugin.cc b/src/plugin/Plugin.cc
index 941ee0038c..77b98c9760 100644
--- a/src/plugin/Plugin.cc
+++ b/src/plugin/Plugin.cc
@@ -471,10 +471,18 @@ void Plugin::MetaHookPost(::plugin::HookType hook, const HookArgumentList& args,
 
 void Plugin::MetaHookPre(::zeek::plugin::HookType hook, const HookArgumentList& args)
 	{
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	MetaHookPre(static_cast<::plugin::HookType>(hook), args);
+#pragma GCC diagnostic pop
 	}
 
 void Plugin::MetaHookPost(::zeek::plugin::HookType hook, const HookArgumentList& args, HookArgument result)
 	{
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	MetaHookPost(static_cast<::plugin::HookType>(hook), args, result);
+#pragma GCC diagnostic pop
 	}
 
 void Plugin::InitializeComponents()
diff --git a/src/zeek.bif b/src/zeek.bif
index 006df997e2..d63bf1453f 100644
--- a/src/zeek.bif
+++ b/src/zeek.bif
@@ -1918,7 +1918,7 @@ function global_sizes%(%): var_sizes
 
 	for ( const auto& global : globals )
 		{
-		auto id = global.second;
+		auto& id = global.second;
 		if ( id->HasVal() )
 			{
 			auto id_name = make_intrusive<StringVal>(id->Name());
@@ -1946,7 +1946,7 @@ function global_ids%(%): id_table
 
 	for ( const auto& global : globals )
 		{
-		zeek::detail::ID* id = global.second.get();
+		const auto& id = global.second;
 		static auto script_id = zeek::id::find_type<zeek::RecordType>("script_id");
 		auto rec = make_intrusive<RecordVal>(script_id);
 		rec->Assign(0, make_intrusive<StringVal>(type_name(id->GetType()->Tag())));