diff --git a/src/Attr.h b/src/Attr.h
index f09b3a7a6e..7271bdd1f6 100644
--- a/src/Attr.h
+++ b/src/Attr.h
@@ -34,7 +34,7 @@ typedef enum {
 #define NUM_ATTRS (int(ATTR_DEPRECATED) + 1)
 } attr_tag;
 
-class Attr : public BroObj {
+class Attr final : public BroObj {
 public:
 	Attr(attr_tag t, IntrusivePtr<Expr> e);
 	explicit Attr(attr_tag t);
@@ -71,7 +71,7 @@ protected:
 };
 
 // Manages a collection of attributes.
-class Attributes : public BroObj {
+class Attributes final : public BroObj {
 public:
 	Attributes(attr_list* a, IntrusivePtr<BroType> t, bool in_record, bool is_global);
 	~Attributes() override;
diff --git a/src/Conn.h b/src/Conn.h
index 4211520525..53ece49bef 100644
--- a/src/Conn.h
+++ b/src/Conn.h
@@ -59,7 +59,7 @@ static inline int addr_port_canon_lt(const IPAddr& addr1, uint32_t p1,
 
 namespace analyzer { class Analyzer; }
 
-class Connection : public BroObj {
+class Connection final : public BroObj {
 public:
 	Connection(NetSessions* s, const ConnIDKey& k, double t, const ConnID* id,
 	           uint32_t flow, const Packet* pkt, const EncapsulationStack* arg_encap);
diff --git a/src/Event.h b/src/Event.h
index 6bf43a0aa4..9f353ad235 100644
--- a/src/Event.h
+++ b/src/Event.h
@@ -14,7 +14,7 @@
 
 class EventMgr;
 
-class Event : public BroObj {
+class Event final : public BroObj {
 public:
 	Event(EventHandlerPtr handler, zeek::Args args,
 	      SourceID src = SOURCE_LOCAL, analyzer::ID aid = 0,
diff --git a/src/Expr.h b/src/Expr.h
index 8013d8129a..33b3a05b8b 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -202,7 +202,7 @@ public:
 		return (IndexExpr*) this;
 		}
 
-	void Describe(ODesc* d) const override;
+	void Describe(ODesc* d) const override final;
 
 	virtual TraversalCode Traverse(TraversalCallback* cb) const = 0;
 
@@ -232,7 +232,7 @@ protected:
 	bool paren;
 };
 
-class NameExpr : public Expr {
+class NameExpr final : public Expr {
 public:
 	explicit NameExpr(IntrusivePtr<ID> id, bool const_init = false);
 
@@ -252,7 +252,7 @@ protected:
 	bool in_const_init;
 };
 
-class ConstExpr : public Expr {
+class ConstExpr final : public Expr {
 public:
 	explicit ConstExpr(IntrusivePtr<Val> val);
 
@@ -350,7 +350,7 @@ protected:
 	IntrusivePtr<Expr> op2;
 };
 
-class CloneExpr : public UnaryExpr {
+class CloneExpr final : public UnaryExpr {
 public:
 	explicit CloneExpr(IntrusivePtr<Expr> op);
 	IntrusivePtr<Val> Eval(Frame* f) const override;
@@ -359,7 +359,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class IncrExpr : public UnaryExpr {
+class IncrExpr final : public UnaryExpr {
 public:
 	IncrExpr(BroExprTag tag, IntrusivePtr<Expr> op);
 
@@ -368,7 +368,7 @@ public:
 	bool IsPure() const override;
 };
 
-class ComplementExpr : public UnaryExpr {
+class ComplementExpr final : public UnaryExpr {
 public:
 	explicit ComplementExpr(IntrusivePtr<Expr> op);
 
@@ -376,7 +376,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class NotExpr : public UnaryExpr {
+class NotExpr final : public UnaryExpr {
 public:
 	explicit NotExpr(IntrusivePtr<Expr> op);
 
@@ -384,7 +384,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class PosExpr : public UnaryExpr {
+class PosExpr final : public UnaryExpr {
 public:
 	explicit PosExpr(IntrusivePtr<Expr> op);
 
@@ -392,7 +392,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class NegExpr : public UnaryExpr {
+class NegExpr final : public UnaryExpr {
 public:
 	explicit NegExpr(IntrusivePtr<Expr> op);
 
@@ -400,7 +400,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class SizeExpr : public UnaryExpr {
+class SizeExpr final : public UnaryExpr {
 public:
 	explicit SizeExpr(IntrusivePtr<Expr> op);
 	IntrusivePtr<Val> Eval(Frame* f) const override;
@@ -409,36 +409,36 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class AddExpr : public BinaryExpr {
+class AddExpr final : public BinaryExpr {
 public:
 	AddExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	void Canonicize() override;
 };
 
-class AddToExpr : public BinaryExpr {
+class AddToExpr final : public BinaryExpr {
 public:
 	AddToExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	IntrusivePtr<Val> Eval(Frame* f) const override;
 };
 
-class RemoveFromExpr : public BinaryExpr {
+class RemoveFromExpr final : public BinaryExpr {
 public:
 	RemoveFromExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	IntrusivePtr<Val> Eval(Frame* f) const override;
 };
 
-class SubExpr : public BinaryExpr {
+class SubExpr final : public BinaryExpr {
 public:
 	SubExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 };
 
-class TimesExpr : public BinaryExpr {
+class TimesExpr final : public BinaryExpr {
 public:
 	TimesExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	void Canonicize() override;
 };
 
-class DivideExpr : public BinaryExpr {
+class DivideExpr final : public BinaryExpr {
 public:
 	DivideExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 
@@ -446,12 +446,12 @@ protected:
 	IntrusivePtr<Val> AddrFold(Val* v1, Val* v2) const override;
 };
 
-class ModExpr : public BinaryExpr {
+class ModExpr final : public BinaryExpr {
 public:
 	ModExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 };
 
-class BoolExpr : public BinaryExpr {
+class BoolExpr final : public BinaryExpr {
 public:
 	BoolExpr(BroExprTag tag, IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 
@@ -459,12 +459,12 @@ public:
 	IntrusivePtr<Val> DoSingleEval(Frame* f, IntrusivePtr<Val> v1, Expr* op2) const;
 };
 
-class BitExpr : public BinaryExpr {
+class BitExpr final : public BinaryExpr {
 public:
 	BitExpr(BroExprTag tag, IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 };
 
-class EqExpr : public BinaryExpr {
+class EqExpr final : public BinaryExpr {
 public:
 	EqExpr(BroExprTag tag, IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	void Canonicize() override;
@@ -473,13 +473,13 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v1, Val* v2) const override;
 };
 
-class RelExpr : public BinaryExpr {
+class RelExpr final : public BinaryExpr {
 public:
 	RelExpr(BroExprTag tag, IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 	void Canonicize() override;
 };
 
-class CondExpr : public Expr {
+class CondExpr final : public Expr {
 public:
 	CondExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2, IntrusivePtr<Expr> op3);
 
@@ -500,7 +500,7 @@ protected:
 	IntrusivePtr<Expr> op3;
 };
 
-class RefExpr : public UnaryExpr {
+class RefExpr final : public UnaryExpr {
 public:
 	explicit RefExpr(IntrusivePtr<Expr> op);
 
@@ -530,14 +530,14 @@ protected:
 	IntrusivePtr<Val> val;	// optional
 };
 
-class IndexSliceAssignExpr : public AssignExpr {
+class IndexSliceAssignExpr final : public AssignExpr {
 public:
 	IndexSliceAssignExpr(IntrusivePtr<Expr> op1,
 	                     IntrusivePtr<Expr> op2, bool is_init);
 	IntrusivePtr<Val> Eval(Frame* f) const override;
 };
 
-class IndexExpr : public BinaryExpr {
+class IndexExpr final : public BinaryExpr {
 public:
 	IndexExpr(IntrusivePtr<Expr> op1,
 	          IntrusivePtr<ListExpr> op2, bool is_slice = false);
@@ -567,7 +567,7 @@ protected:
 	bool is_slice;
 };
 
-class FieldExpr : public UnaryExpr {
+class FieldExpr final : public UnaryExpr {
 public:
 	FieldExpr(IntrusivePtr<Expr> op, const char* field_name);
 	~FieldExpr() override;
@@ -594,7 +594,7 @@ protected:
 
 // "rec?$fieldname" is true if the value of $fieldname in rec is not nil.
 // "rec?$$attrname" is true if the attribute attrname is not nil.
-class HasFieldExpr : public UnaryExpr {
+class HasFieldExpr final : public UnaryExpr {
 public:
 	HasFieldExpr(IntrusivePtr<Expr> op, const char* field_name);
 	~HasFieldExpr() override;
@@ -610,7 +610,7 @@ protected:
 	int field;
 };
 
-class RecordConstructorExpr : public UnaryExpr {
+class RecordConstructorExpr final : public UnaryExpr {
 public:
 	explicit RecordConstructorExpr(IntrusivePtr<ListExpr> constructor_list);
 	~RecordConstructorExpr() override;
@@ -622,7 +622,7 @@ protected:
 	void ExprDescribe(ODesc* d) const override;
 };
 
-class TableConstructorExpr : public UnaryExpr {
+class TableConstructorExpr final : public UnaryExpr {
 public:
 	TableConstructorExpr(IntrusivePtr<ListExpr> constructor_list, attr_list* attrs,
 	                     IntrusivePtr<BroType> arg_type = nullptr);
@@ -640,7 +640,7 @@ protected:
 	Attributes* attrs;
 };
 
-class SetConstructorExpr : public UnaryExpr {
+class SetConstructorExpr final : public UnaryExpr {
 public:
 	SetConstructorExpr(IntrusivePtr<ListExpr> constructor_list, attr_list* attrs,
 	                   IntrusivePtr<BroType> arg_type = nullptr);
@@ -658,7 +658,7 @@ protected:
 	Attributes* attrs;
 };
 
-class VectorConstructorExpr : public UnaryExpr {
+class VectorConstructorExpr final : public UnaryExpr {
 public:
 	explicit VectorConstructorExpr(IntrusivePtr<ListExpr> constructor_list,
 	                               IntrusivePtr<BroType> arg_type = nullptr);
@@ -671,7 +671,7 @@ protected:
 	void ExprDescribe(ODesc* d) const override;
 };
 
-class FieldAssignExpr : public UnaryExpr {
+class FieldAssignExpr final : public UnaryExpr {
 public:
 	FieldAssignExpr(const char* field_name, IntrusivePtr<Expr> value);
 
@@ -686,7 +686,7 @@ protected:
 	string field_name;
 };
 
-class ArithCoerceExpr : public UnaryExpr {
+class ArithCoerceExpr final : public UnaryExpr {
 public:
 	ArithCoerceExpr(IntrusivePtr<Expr> op, TypeTag t);
 
@@ -695,7 +695,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class RecordCoerceExpr : public UnaryExpr {
+class RecordCoerceExpr final : public UnaryExpr {
 public:
 	RecordCoerceExpr(IntrusivePtr<Expr> op, IntrusivePtr<RecordType> r);
 	~RecordCoerceExpr() override;
@@ -710,7 +710,7 @@ protected:
 	int map_size;	// equivalent to Type()->AsRecordType()->NumFields()
 };
 
-class TableCoerceExpr : public UnaryExpr {
+class TableCoerceExpr final : public UnaryExpr {
 public:
 	TableCoerceExpr(IntrusivePtr<Expr> op, IntrusivePtr<TableType> r);
 	~TableCoerceExpr() override;
@@ -719,7 +719,7 @@ protected:
 	IntrusivePtr<Val> Fold(Val* v) const override;
 };
 
-class VectorCoerceExpr : public UnaryExpr {
+class VectorCoerceExpr final : public UnaryExpr {
 public:
 	VectorCoerceExpr(IntrusivePtr<Expr> op, IntrusivePtr<VectorType> v);
 	~VectorCoerceExpr() override;
@@ -730,7 +730,7 @@ protected:
 
 // An internal operator for flattening array indices that are records
 // into a list of individual values.
-class FlattenExpr : public UnaryExpr {
+class FlattenExpr final : public UnaryExpr {
 public:
 	explicit FlattenExpr(IntrusivePtr<Expr> op);
 
@@ -752,7 +752,7 @@ protected:
 	zeek::Args args;
 };
 
-class ScheduleExpr : public Expr {
+class ScheduleExpr final : public Expr {
 public:
 	ScheduleExpr(IntrusivePtr<Expr> when, IntrusivePtr<EventExpr> event);
 
@@ -772,7 +772,7 @@ protected:
 	IntrusivePtr<EventExpr> event;
 };
 
-class InExpr : public BinaryExpr {
+class InExpr final : public BinaryExpr {
 public:
 	InExpr(IntrusivePtr<Expr> op1, IntrusivePtr<Expr> op2);
 
@@ -781,7 +781,7 @@ protected:
 
 };
 
-class CallExpr : public Expr {
+class CallExpr final : public Expr {
 public:
 	CallExpr(IntrusivePtr<Expr> func, IntrusivePtr<ListExpr> args,
 	         bool in_hook = false);
@@ -808,7 +808,7 @@ protected:
  * On evaluation, captures the frame that it is evaluated in. This becomes
  * the closure for the instance of the function that it creates.
  */
-class LambdaExpr : public Expr {
+class LambdaExpr final : public Expr {
 public:
 	LambdaExpr(std::unique_ptr<function_ingredients> ingredients,
 		   id_list outer_ids);
@@ -828,7 +828,7 @@ private:
 	std::string my_name;
 };
 
-class EventExpr : public Expr {
+class EventExpr final : public Expr {
 public:
 	EventExpr(const char* name, IntrusivePtr<ListExpr> args);
 
@@ -880,12 +880,12 @@ protected:
 };
 
 
-class RecordAssignExpr : public ListExpr {
+class RecordAssignExpr final : public ListExpr {
 public:
 	RecordAssignExpr(const IntrusivePtr<Expr>& record, const IntrusivePtr<Expr>& init_list, bool is_init);
 };
 
-class CastExpr : public UnaryExpr {
+class CastExpr final : public UnaryExpr {
 public:
 	CastExpr(IntrusivePtr<Expr> op, IntrusivePtr<BroType> t);
 
@@ -894,7 +894,7 @@ protected:
 	void ExprDescribe(ODesc* d) const override;
 };
 
-class IsExpr : public UnaryExpr {
+class IsExpr final : public UnaryExpr {
 public:
 	IsExpr(IntrusivePtr<Expr> op, IntrusivePtr<BroType> t);
 
diff --git a/src/File.h b/src/File.h
index 2d10237a76..7f14d2ad73 100644
--- a/src/File.h
+++ b/src/File.h
@@ -19,7 +19,7 @@ class Attributes;
 class BroType;
 class RecordVal;
 
-class BroFile : public BroObj {
+class BroFile final : public BroObj {
 public:
 	explicit BroFile(FILE* arg_f);
 	BroFile(FILE* arg_f, const char* filename, const char* access);
diff --git a/src/Func.h b/src/Func.h
index c414e3ac85..385fd016a2 100644
--- a/src/Func.h
+++ b/src/Func.h
@@ -118,7 +118,7 @@ protected:
 };
 
 
-class BroFunc : public Func {
+class BroFunc final : public Func {
 public:
 	BroFunc(ID* id, IntrusivePtr<Stmt> body, id_list* inits, size_t frame_size, int priority);
 	~BroFunc() override;
@@ -193,7 +193,7 @@ private:
 
 using built_in_func = Val* (*)(Frame* frame, const zeek::Args* args);
 
-class BuiltinFunc : public Func {
+class BuiltinFunc final : public Func {
 public:
 	BuiltinFunc(built_in_func func, const char* name, bool is_pure);
 	~BuiltinFunc() override;
diff --git a/src/ID.h b/src/ID.h
index ee96ea7845..a076a2d37a 100644
--- a/src/ID.h
+++ b/src/ID.h
@@ -21,7 +21,7 @@ class Attributes;
 typedef enum { INIT_NONE, INIT_FULL, INIT_EXTRA, INIT_REMOVE, } init_class;
 typedef enum { SCOPE_FUNCTION, SCOPE_MODULE, SCOPE_GLOBAL } IDScope;
 
-class ID : public BroObj, public notifier::Modifiable {
+class ID final : public BroObj, public notifier::Modifiable {
 public:
 	ID(const char* name, IDScope arg_scope, bool arg_is_export);
 	~ID() override;
diff --git a/src/Stmt.h b/src/Stmt.h
index cd28c60172..0fb57c7b23 100644
--- a/src/Stmt.h
+++ b/src/Stmt.h
@@ -103,7 +103,7 @@ protected:
 	IntrusivePtr<ListExpr> l;
 };
 
-class PrintStmt : public ExprListStmt {
+class PrintStmt final : public ExprListStmt {
 public:
 	template<typename L>
 	explicit PrintStmt(L&& l) : ExprListStmt(STMT_PRINT, std::forward<L>(l)) { }
@@ -136,7 +136,7 @@ protected:
 	IntrusivePtr<Expr> e;
 };
 
-class IfStmt : public ExprStmt {
+class IfStmt final : public ExprStmt {
 public:
 	IfStmt(IntrusivePtr<Expr> test, IntrusivePtr<Stmt> s1, IntrusivePtr<Stmt> s2);
 	~IfStmt() override;
@@ -156,7 +156,7 @@ protected:
 	IntrusivePtr<Stmt> s2;
 };
 
-class Case : public BroObj {
+class Case final : public BroObj {
 public:
 	Case(IntrusivePtr<ListExpr> c, id_list* types, IntrusivePtr<Stmt> arg_s);
 	~Case() override;
@@ -180,9 +180,9 @@ protected:
 	IntrusivePtr<Stmt> s;
 };
 
-typedef PList<Case> case_list;
+using case_list = PList<Case>;
 
-class SwitchStmt : public ExprStmt {
+class SwitchStmt final : public ExprStmt {
 public:
 	SwitchStmt(IntrusivePtr<Expr> index, case_list* cases);
 	~SwitchStmt() override;
@@ -223,7 +223,7 @@ protected:
 	std::vector<std::pair<ID*, int>> case_label_type_list;
 };
 
-class AddStmt : public ExprStmt {
+class AddStmt final : public ExprStmt {
 public:
 	explicit AddStmt(IntrusivePtr<Expr> e);
 
@@ -233,7 +233,7 @@ public:
 	TraversalCode Traverse(TraversalCallback* cb) const override;
 };
 
-class DelStmt : public ExprStmt {
+class DelStmt final : public ExprStmt {
 public:
 	explicit DelStmt(IntrusivePtr<Expr> e);
 
@@ -243,7 +243,7 @@ public:
 	TraversalCode Traverse(TraversalCallback* cb) const override;
 };
 
-class EventStmt : public ExprStmt {
+class EventStmt final : public ExprStmt {
 public:
 	explicit EventStmt(IntrusivePtr<EventExpr> e);
 
@@ -255,7 +255,7 @@ protected:
 	IntrusivePtr<EventExpr> event_expr;
 };
 
-class WhileStmt : public Stmt {
+class WhileStmt final : public Stmt {
 public:
 
 	WhileStmt(IntrusivePtr<Expr> loop_condition, IntrusivePtr<Stmt> body);
@@ -274,7 +274,7 @@ protected:
 	IntrusivePtr<Stmt> body;
 };
 
-class ForStmt : public ExprStmt {
+class ForStmt final : public ExprStmt {
 public:
 	ForStmt(id_list* loop_vars, IntrusivePtr<Expr> loop_expr);
 	// Special constructor for key value for loop.
@@ -303,7 +303,7 @@ protected:
 	IntrusivePtr<ID> value_var;
 };
 
-class NextStmt : public Stmt {
+class NextStmt final : public Stmt {
 public:
 	NextStmt() : Stmt(STMT_NEXT)	{ }
 
@@ -317,7 +317,7 @@ public:
 protected:
 };
 
-class BreakStmt : public Stmt {
+class BreakStmt final : public Stmt {
 public:
 	BreakStmt() : Stmt(STMT_BREAK)	{ }
 
@@ -331,7 +331,7 @@ public:
 protected:
 };
 
-class FallthroughStmt : public Stmt {
+class FallthroughStmt final : public Stmt {
 public:
 	FallthroughStmt() : Stmt(STMT_FALLTHROUGH)	{ }
 
@@ -345,7 +345,7 @@ public:
 protected:
 };
 
-class ReturnStmt : public ExprStmt {
+class ReturnStmt final : public ExprStmt {
 public:
 	explicit ReturnStmt(IntrusivePtr<Expr> e);
 
@@ -374,7 +374,7 @@ protected:
 	stmt_list stmts;
 };
 
-class EventBodyList : public StmtList {
+class EventBodyList final : public StmtList {
 public:
 	EventBodyList() : StmtList()
 		{ topmost = false; tag = STMT_EVENT_BODY_LIST; }
@@ -391,7 +391,7 @@ protected:
 	bool topmost;
 };
 
-class InitStmt : public Stmt {
+class InitStmt final : public Stmt {
 public:
 	explicit InitStmt(id_list* arg_inits);
 
@@ -409,7 +409,7 @@ protected:
 	id_list* inits;
 };
 
-class NullStmt : public Stmt {
+class NullStmt final : public Stmt {
 public:
 	NullStmt() : Stmt(STMT_NULL)	{ }
 
@@ -421,7 +421,7 @@ public:
 	TraversalCode Traverse(TraversalCallback* cb) const override;
 };
 
-class WhenStmt : public Stmt {
+class WhenStmt final : public Stmt {
 public:
 	// s2 is null if no timeout block given.
 	WhenStmt(IntrusivePtr<Expr> cond,
diff --git a/src/Trigger.h b/src/Trigger.h
index 5d91b17aa0..8bf8c77abc 100644
--- a/src/Trigger.h
+++ b/src/Trigger.h
@@ -25,7 +25,7 @@ using std::map;
 class TriggerTimer;
 class TriggerTraversalCallback;
 
-class Trigger : public BroObj, public notifier::Receiver {
+class Trigger final : public BroObj, public notifier::Receiver {
 public:
 	// Don't access Trigger objects; they take care of themselves after
 	// instantiation.  Note that if the condition is already true, the
diff --git a/src/Type.h b/src/Type.h
index 9686bcdf9f..7072e76524 100644
--- a/src/Type.h
+++ b/src/Type.h
@@ -345,7 +345,7 @@ private:
 	static TypeAliasMap type_aliases;
 };
 
-class TypeList : public BroType {
+class TypeList final : public BroType {
 public:
 	explicit TypeList(IntrusivePtr<BroType> arg_pure_type = nullptr)
 		: BroType(TYPE_LIST), pure_type(std::move(arg_pure_type))
@@ -424,7 +424,7 @@ protected:
 	TypeList* ExpandRecordIndex(RecordType* rt) const;
 };
 
-class SetType : public TableType {
+class SetType final : public TableType {
 public:
 	SetType(IntrusivePtr<TypeList> ind, IntrusivePtr<ListExpr> arg_elements);
 	~SetType() override;
@@ -437,7 +437,7 @@ protected:
 	IntrusivePtr<ListExpr> elements;
 };
 
-class FuncType : public BroType {
+class FuncType final : public BroType {
 public:
 	FuncType(IntrusivePtr<RecordType> args, IntrusivePtr<BroType> yield,
 	         function_flavor f);
@@ -472,7 +472,7 @@ protected:
 	function_flavor flavor;
 };
 
-class TypeType : public BroType {
+class TypeType final : public BroType {
 public:
 	explicit TypeType(IntrusivePtr<BroType> t) : BroType(TYPE_TYPE), type(std::move(t)) {}
 	TypeType* ShallowClone() override { return new TypeType(type); }
@@ -501,7 +501,7 @@ public:
 
 typedef PList<TypeDecl> type_decl_list;
 
-class RecordType : public BroType {
+class RecordType final : public BroType {
 public:
 	explicit RecordType(type_decl_list* types);
 	RecordType* ShallowClone() override;
@@ -565,13 +565,13 @@ protected:
 	type_decl_list* types;
 };
 
-class SubNetType : public BroType {
+class SubNetType final : public BroType {
 public:
 	SubNetType();
 	void Describe(ODesc* d) const override;
 };
 
-class FileType : public BroType {
+class FileType final : public BroType {
 public:
 	explicit FileType(IntrusivePtr<BroType> yield_type);
 	FileType* ShallowClone() override { return new FileType(yield); }
@@ -585,7 +585,7 @@ protected:
 	IntrusivePtr<BroType> yield;
 };
 
-class OpaqueType : public BroType {
+class OpaqueType final : public BroType {
 public:
 	explicit OpaqueType(const std::string& name);
 	OpaqueType* ShallowClone() override { return new OpaqueType(name); }
@@ -602,7 +602,7 @@ protected:
 	std::string name;
 };
 
-class EnumType : public BroType {
+class EnumType final : public BroType {
 public:
 	typedef std::list<std::pair<std::string, bro_int_t> > enum_name_list;
 
@@ -655,7 +655,7 @@ protected:
 	bro_int_t counter;
 };
 
-class VectorType : public BroType {
+class VectorType final : public BroType {
 public:
 	explicit VectorType(IntrusivePtr<BroType> t);
 	VectorType* ShallowClone() override;
diff --git a/src/Val.h b/src/Val.h
index c8c19bdb45..4d3e90b30e 100644
--- a/src/Val.h
+++ b/src/Val.h
@@ -458,7 +458,7 @@ extern ValManager* val_mgr;
 #define Hours (60*Minutes)
 #define Days (24*Hours)
 
-class IntervalVal : public Val {
+class IntervalVal final : public Val {
 public:
 	IntervalVal(double quantity, double units);
 
@@ -469,7 +469,7 @@ protected:
 };
 
 
-class PortVal : public Val {
+class PortVal final : public Val {
 public:
 	IntrusivePtr<Val> SizeVal() const override;
 
@@ -505,7 +505,7 @@ protected:
 	IntrusivePtr<Val> DoClone(CloneState* state) override;
 };
 
-class AddrVal : public Val {
+class AddrVal final : public Val {
 public:
 	explicit AddrVal(const char* text);
 	explicit AddrVal(const std::string& text);
@@ -524,7 +524,7 @@ protected:
 	IntrusivePtr<Val> DoClone(CloneState* state) override;
 };
 
-class SubNetVal : public Val {
+class SubNetVal final : public Val {
 public:
 	explicit SubNetVal(const char* text);
 	SubNetVal(const char* text, int width);
@@ -549,7 +549,7 @@ protected:
 	IntrusivePtr<Val> DoClone(CloneState* state) override;
 };
 
-class StringVal : public Val {
+class StringVal final : public Val {
 public:
 	explicit StringVal(BroString* s);
 	explicit StringVal(const char* s);
@@ -579,7 +579,7 @@ protected:
 	IntrusivePtr<Val> DoClone(CloneState* state) override;
 };
 
-class PatternVal : public Val {
+class PatternVal final : public Val {
 public:
 	explicit PatternVal(RE_Matcher* re);
 	~PatternVal() override;
@@ -597,7 +597,7 @@ protected:
 
 // ListVals are mainly used to index tables that have more than one
 // element in their index.
-class ListVal : public Val {
+class ListVal final : public Val {
 public:
 	explicit ListVal(TypeTag t);
 	~ListVal() override;
@@ -691,7 +691,7 @@ class CompositeHash;
 class HashKey;
 class Frame;
 
-class TableVal : public Val, public notifier::Modifiable {
+class TableVal final : public Val, public notifier::Modifiable {
 public:
 	explicit TableVal(IntrusivePtr<TableType> t, IntrusivePtr<Attributes> attrs = nullptr);
 	~TableVal() override;
@@ -878,7 +878,7 @@ protected:
 	static ParseTimeTableStates parse_time_table_states;
 };
 
-class RecordVal : public Val, public notifier::Modifiable {
+class RecordVal final : public Val, public notifier::Modifiable {
 public:
 	explicit RecordVal(RecordType* t, bool init_fields = true);
 	~RecordVal() override;
@@ -947,7 +947,7 @@ protected:
 	static RecordTypeValMap parse_time_records;
 };
 
-class EnumVal : public Val {
+class EnumVal final : public Val {
 public:
 	IntrusivePtr<Val> SizeVal() const override;
 
@@ -964,7 +964,7 @@ protected:
 };
 
 
-class VectorVal : public Val, public notifier::Modifiable {
+class VectorVal final : public Val, public notifier::Modifiable {
 public:
 	explicit VectorVal(VectorType* t);
 	~VectorVal() override;