diff --git a/src/Expr.h b/src/Expr.h
index 0cfdf84a2c..2dde29e52c 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -304,11 +304,11 @@ public:
 	// True if this expression can be the RHS for a field assignment.
 	bool IsFieldAssignable(const Expr* e) const;
 
-	// True if the expression will transform to one of another type
-	// upon reduction, for non-constant operands.  "Transform" means
-	// something beyond assignment to a temporary.  Necessary so that
-	// we know to fully reduce such expressions if they're the RHS
-	// of an assignment.
+	// True if the expression will transform to one of another AST node
+	// (perhaps of the same type) upon reduction, for non-constant
+	// operands.  "Transform" means something beyond assignment to a
+	// temporary.  Necessary so that we know to fully reduce such
+	// expressions if they're the RHS of an assignment.
 	virtual bool WillTransform(Reducer* c) const { return false; }
 
 	// The same, but for the expression when used in a conditional context.
diff --git a/src/script_opt/Expr.cc b/src/script_opt/Expr.cc
index 83480680e7..8c99d6f5de 100644
--- a/src/script_opt/Expr.cc
+++ b/src/script_opt/Expr.cc
@@ -1812,8 +1812,9 @@ ExprPtr AssignExpr::Reduce(Reducer* c, StmtPtr& red_stmt)
 	if ( op2->WillTransform(c) )
 		{
 		StmtPtr xform_stmt;
+		StmtPtr lhs_stmt = lhs_ref->ReduceToLHS(c);
 		op2 = op2->ReduceToSingleton(c, xform_stmt);
-		red_stmt = MergeStmts(rhs_reduce, xform_stmt);
+		red_stmt = MergeStmts(lhs_stmt, rhs_reduce, xform_stmt);
 		return ThisPtr();
 		}