diff --git a/src/Frame.h b/src/Frame.h
index 7c081939c1..a0fc5146d5 100644
--- a/src/Frame.h
+++ b/src/Frame.h
@@ -53,6 +53,13 @@ public:
 	 */
 	Frame(int size, const ScriptFunc* func, const zeek::Args* fn_args);
 
+	/**
+	 * Returns the size of the frame.
+	 *
+	 * @return the number of elements in the frame.
+	 */
+	int FrameSize() const { return size; }
+
 	/**
 	 * @param n the index to get.
 	 * @return the value at index *n* of the underlying array.
diff --git a/src/Func.h b/src/Func.h
index 06f2d26306..14aad967aa 100644
--- a/src/Func.h
+++ b/src/Func.h
@@ -344,14 +344,19 @@ public:
 	const IDPtr& GetID() const { return id; }
 
 	const StmtPtr& Body() const { return body; }
-	void SetBody(StmtPtr _body) { body = std::move(_body); }
 
 	const auto& Inits() const { return inits; }
+	void ClearInits() { inits.clear(); }
+
 	size_t FrameSize() const { return frame_size; }
 	int Priority() const { return priority; }
 	const ScopePtr& Scope() const { return scope; }
 	const auto& Groups() const { return groups; }
 
+	// Used by script optimization to update lambda ingredients
+	// after compilation.
+	void SetFrameSize(size_t _frame_size) { frame_size = std::move(_frame_size); }
+
 private:
 	IDPtr id;
 	StmtPtr body;
diff --git a/src/Val.cc b/src/Val.cc
index 0288cc1738..6c9e214bc2 100644
--- a/src/Val.cc
+++ b/src/Val.cc
@@ -2787,6 +2787,11 @@ void TableVal::InitDefaultFunc(detail::Frame* f)
 	def_val = def_attr->GetExpr()->Eval(f);
 	}
 
+void TableVal::InitDefaultVal(ValPtr _def_val)
+	{
+	def_val = std::move(_def_val);
+	}
+
 void TableVal::InitTimer(double delay)
 	{
 	timer = new TableValTimer(this, run_state::network_time + delay);
diff --git a/src/Val.h b/src/Val.h
index 75dd006df3..6909f4807c 100644
--- a/src/Val.h
+++ b/src/Val.h
@@ -968,9 +968,13 @@ public:
 
 	// If the &default attribute is not a function, or the function has
 	// already been initialized, this does nothing. Otherwise, evaluates
-	// the function in the frame allowing it to capture its closure.
+	// the function in the frame, allowing it to capture its closure.
 	void InitDefaultFunc(detail::Frame* f);
 
+	// An alternative that assigns the default value directly.  Used
+	// by ZAM compilation.
+	void InitDefaultVal(ValPtr def_val);
+
 	void ClearTimer(detail::Timer* t)
 		{
 		if ( timer == t )