diff --git a/src/Expr.cc b/src/Expr.cc
index 634918c557..29666c5b60 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -40,9 +40,7 @@ const char* expr_name(BroExprTag t)
 		"()", "function()", "event", "schedule",
 		"coerce", "record_coerce", "table_coerce", "vector_coerce",
 		"sizeof", "cast", "is", "[:]=",
-
-#include "zeek/script_opt/ExprOpt-Names.h"
-
+		"inline()",
 		"nop",
 
 	};
diff --git a/src/Expr.h b/src/Expr.h
index 7662bac81d..d93d51597b 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -67,9 +67,7 @@ enum BroExprTag : int {
 	EXPR_CAST,
 	EXPR_IS,
 	EXPR_INDEX_SLICE_ASSIGN,
-
-#include "zeek/script_opt/ExprOpt-Enums.h"
-
+	EXPR_INLINE,
 	EXPR_NOP,
 
 #define NUM_EXPRS (int(EXPR_NOP) + 1)
@@ -196,7 +194,39 @@ public:
 
 	virtual TraversalCode Traverse(TraversalCallback* cb) const = 0;
 
-#include "zeek/script_opt/ExprOpt-Public.h"
+	// Returns a duplicate of the expression.
+	virtual ExprPtr Duplicate() = 0;
+
+	// Recursively traverses the AST to inline eligible function calls.
+	virtual ExprPtr Inline(Inliner* inl)	{ return ThisPtr(); }
+
+	// Access to the original expression from which this one is derived,
+	// or this one if we don't have an original.  Returns a bare pointer
+	// rather than an ExprPtr to emphasize that the access is read-only.
+	const Expr* Original() const
+		{ return original ? original->Original() : this; }
+
+	// Designate the given Expr node as the original for this one.
+	void SetOriginal(ExprPtr _orig)
+		{
+		if ( ! original )
+			original = std::move(_orig);
+		}
+
+	// A convenience function for taking a newly-created Expr,
+	// making it point to us as the successor, and returning it.
+	//
+	// Takes an Expr* rather than a ExprPtr to de-clutter the calling
+	// code, which is always passing in "new XyzExpr(...)".  This
+	// call, as a convenient side effect, transforms that bare pointer
+	// into an ExprPtr.
+	virtual ExprPtr SetSucc(Expr* succ)
+		{
+		succ->SetOriginal(ThisPtr());
+		if ( IsParen() )
+			succ->MarkParen();
+		return {AdoptRef{}, succ};
+		}
 
 protected:
 	Expr() = default;
@@ -223,7 +253,10 @@ protected:
 	TypePtr type;
 	bool paren;
 
-#include "zeek/script_opt/ExprOpt-Private.h"
+	// The original expression from which this statement was
+	// derived, if any.  Used as an aid for generating meaningful
+	// and correctly-localized error messages.
+	ExprPtr original = nullptr;
 };
 
 class NameExpr final : public Expr {
@@ -1100,7 +1133,30 @@ private:
 };
 
 
-#include "zeek/script_opt/ExprOpt-Subclasses.h"
+class InlineExpr : public Expr {
+public:
+	InlineExpr(ListExprPtr arg_args, IDPList* params, StmtPtr body,
+	           int frame_offset, TypePtr ret_type);
+
+	bool IsPure() const override;
+
+	ListExprPtr Args() const	{ return args; }
+	StmtPtr Body() const		{ return body; }
+
+	ValPtr Eval(Frame* f) const override;
+
+	ExprPtr Duplicate() override;
+
+	TraversalCode Traverse(TraversalCallback* cb) const override;
+
+protected:
+	void ExprDescribe(ODesc* d) const override;
+
+	IDPList* params;
+	int frame_offset;
+	ListExprPtr args;
+	StmtPtr body;
+};
 
 
 inline Val* Expr::ExprVal() const
diff --git a/src/StmtBase.h b/src/StmtBase.h
index 1a7759e1f2..8f6b98f561 100644
--- a/src/StmtBase.h
+++ b/src/StmtBase.h
@@ -81,7 +81,37 @@ public:
 
 	virtual TraversalCode Traverse(TraversalCallback* cb) const = 0;
 
-#include "zeek/script_opt/StmtOpt-Public.h"
+	// Returns a duplicate of the statement.
+	virtual StmtPtr Duplicate() = 0;
+
+	// Recursively traverses the AST to inline eligible function calls.
+	virtual void Inline(Inliner* inl)	{ }
+
+	// Access to the original statement from which this one is derived,
+	// or this one if we don't have an original.  Returns a bare pointer
+	// rather than a StmtPtr to emphasize that the access is read-only.
+	const Stmt* Original() const
+		{ return original ? original->Original() : this; }
+
+	// Designate the given Stmt node as the original for this one.
+	void SetOriginal(StmtPtr _orig)
+		{
+		if ( ! original )
+			original = std::move(_orig);
+		}
+
+	// A convenience function for taking a newly-created Stmt,
+	// making it point to us as the successor, and returning it.
+	//
+	// Takes a Stmt* rather than a StmtPtr to de-clutter the calling
+	// code, which is always passing in "new XyzStmt(...)".  This
+	// call, as a convenient side effect, transforms that bare pointer
+	// into a StmtPtr.
+	virtual StmtPtr SetSucc(Stmt* succ)
+		{
+		succ->SetOriginal({NewRef{}, this});
+		return {AdoptRef{}, succ};
+		}
 
 protected:
 	explicit Stmt(StmtTag arg_tag);
@@ -97,7 +127,10 @@ protected:
 	mutable double last_access;	// time of last execution
 	mutable uint32_t access_count;	// number of executions
 
-#include "zeek/script_opt/StmtOpt-Private.h"
+	// The original statement from which this statement was
+	// derived, if any.  Used as an aid for generating meaningful
+	// and correctly-localized error messages.
+	StmtPtr original = nullptr;
 };
 
 } // namespace zeek::detail
diff --git a/src/script_opt/ExprOpt-Enums.h b/src/script_opt/ExprOpt-Enums.h
deleted file mode 100644
index d9000d4875..0000000000
--- a/src/script_opt/ExprOpt-Enums.h
+++ /dev/null
@@ -1,5 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Enums associated with script optimization.
-
-	EXPR_INLINE,
diff --git a/src/script_opt/ExprOpt-Names.h b/src/script_opt/ExprOpt-Names.h
deleted file mode 100644
index 30d361155c..0000000000
--- a/src/script_opt/ExprOpt-Names.h
+++ /dev/null
@@ -1,6 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Names of Expr subclasses associated with script optimization.
-// Companion to script_opt/ExprOpt-Enums.h.
-
-	"inline()",
diff --git a/src/script_opt/ExprOpt-Private.h b/src/script_opt/ExprOpt-Private.h
deleted file mode 100644
index 4065ac7f3f..0000000000
--- a/src/script_opt/ExprOpt-Private.h
+++ /dev/null
@@ -1,13 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Private (protected) Expr methods and member varibles associated
-// with script optimization.  See script_opt/ExprOpt-public.h for
-// why these aren't factored into a separate class.
-//
-// Right now, this file is small, but it will grow as we expand into
-// other forms of script optimization.
-
-        // The original expression from which this statement was
-        // derived, if any.  Used as an aid for generating meaningful
-	// and correctly-localized error messages.
-	ExprPtr original = nullptr;
diff --git a/src/script_opt/ExprOpt-Public.h b/src/script_opt/ExprOpt-Public.h
deleted file mode 100644
index 3384c780c6..0000000000
--- a/src/script_opt/ExprOpt-Public.h
+++ /dev/null
@@ -1,44 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Public Expr methods associated with script optimization.
-//
-// We can't effectively factor these out into a separate class to
-// include via multiple inheritance, because in general they rely
-// on other Expr methods or member variables, so to do so we'd
-// have to (1) make all of the methods virtual, and (2) still
-// include (re-)definitions for them in Expr.h, defeating most
-// of the benefits of using a separate class.
-
-	// Returns a duplicate of the expression.
-	virtual ExprPtr Duplicate() = 0;
-
-	// Recursively traverses the AST to inline eligible function calls.
-	virtual ExprPtr Inline(Inliner* inl)	{ return ThisPtr(); }
-
-	// Access to the original expression from which this one is derived,
-	// or this one if we don't have an original.  Returns a bare pointer
-	// rather than an ExprPtr to emphasize that the access is read-only.
-	const Expr* Original() const
-		{ return original ? original->Original() : this; }
-
-	// Designate the given Expr node as the original for this one.
-	void SetOriginal(ExprPtr _orig)
-		{
-		if ( ! original )
-			original = std::move(_orig);
-		}
-
-	// A convenience function for taking a newly-created Expr,
-	// making it point to us as the successor, and returning it.
-	//
-	// Takes an Expr* rather than a ExprPtr to de-clutter the calling
-	// code, which is always passing in "new XyzExpr(...)".  This
-	// call, as a convenient side effect, transforms that bare pointer
-	// into an ExprPtr.
-	virtual ExprPtr SetSucc(Expr* succ)
-		{
-		succ->SetOriginal(ThisPtr());
-		if ( IsParen() )
-			succ->MarkParen();
-		return {AdoptRef{}, succ};
-		}
diff --git a/src/script_opt/ExprOpt-Subclasses.h b/src/script_opt/ExprOpt-Subclasses.h
deleted file mode 100644
index e4193d6338..0000000000
--- a/src/script_opt/ExprOpt-Subclasses.h
+++ /dev/null
@@ -1,29 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Expr subclasses and associated functions associated with script
-// optimization.
-
-class InlineExpr : public Expr {
-public:
-	InlineExpr(ListExprPtr arg_args, IDPList* params, StmtPtr body,
-			int frame_offset, TypePtr ret_type);
-
-	bool IsPure() const override;
-
-	ListExprPtr Args() const	{ return args; }
-	StmtPtr Body() const		{ return body; }
-
-	ValPtr Eval(Frame* f) const override;
-
-	ExprPtr Duplicate() override;
-
-	TraversalCode Traverse(TraversalCallback* cb) const override;
-
-protected:
-	void ExprDescribe(ODesc* d) const override;
-
-	IDPList* params;
-	int frame_offset;
-	ListExprPtr args;
-	StmtPtr body;
-};
diff --git a/src/script_opt/StmtOpt-Private.h b/src/script_opt/StmtOpt-Private.h
deleted file mode 100644
index 80beffae98..0000000000
--- a/src/script_opt/StmtOpt-Private.h
+++ /dev/null
@@ -1,13 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Private (protected) Stmt methods and member varibles associated
-// with script optimization.  See script_opt/ExprOpt-public.h for
-// why these aren't factored into a separate class.
-//
-// Right now, this file is small, but it will grow as we expand into
-// other forms of script optimization.
-
-	// The original statement from which this statement was
-	// derived, if any.  Used as an aid for generating meaningful
-	// and correctly-localized error messages.
-	StmtPtr original = nullptr;
diff --git a/src/script_opt/StmtOpt-Public.h b/src/script_opt/StmtOpt-Public.h
deleted file mode 100644
index cdc6e2376c..0000000000
--- a/src/script_opt/StmtOpt-Public.h
+++ /dev/null
@@ -1,37 +0,0 @@
-// See the file "COPYING" in the main distribution directory for copyright.
-
-// Stmt methods and member varibles associated with script optimization.
-// See script_opt/ExprOpt-public.h for why these aren't factored into a
-// separate class.
-
-	// Returns a duplicate of the statement.
-	virtual StmtPtr Duplicate() = 0;
-
-	// Recursively traverses the AST to inline eligible function calls.
-	virtual void Inline(Inliner* inl)	{ }
-
-	// Access to the original statement from which this one is derived,
-	// or this one if we don't have an original.  Returns a bare pointer
-	// rather than a StmtPtr to emphasize that the access is read-only.
-	const Stmt* Original() const
-		{ return original ? original->Original() : this; }
-
-	// Designate the given Stmt node as the original for this one.
-	void SetOriginal(StmtPtr _orig)
-		{
-		if ( ! original )
-			original = std::move(_orig);
-		}
-
-	// A convenience function for taking a newly-created Stmt,
-	// making it point to us as the successor, and returning it.
-	//
-	// Takes a Stmt* rather than a StmtPtr to de-clutter the calling
-	// code, which is always passing in "new XyzStmt(...)".  This
-	// call, as a convenient side effect, transforms that bare pointer
-	// into a StmtPtr.
-	virtual StmtPtr SetSucc(Stmt* succ)
-		{
-		succ->SetOriginal({NewRef{}, this});
-		return {AdoptRef{}, succ};
-		}