diff --git a/src/libexpr/include/nix/expr/nixexpr.hh b/src/libexpr/include/nix/expr/nixexpr.hh
index 2682e623b..e04e4f23c 100644
--- a/src/libexpr/include/nix/expr/nixexpr.hh
+++ b/src/libexpr/include/nix/expr/nixexpr.hh
@@ -614,9 +614,13 @@ MakeBinOp(ExprOpNEq, "!=");
 MakeBinOp(ExprOpAnd, "&&");
 MakeBinOp(ExprOpOr, "||");
 MakeBinOp(ExprOpImpl, "->");
-MakeBinOp(ExprOpUpdate, "//");
 MakeBinOp(ExprOpConcatLists, "++");
 
+struct ExprOpUpdate : Expr
+{
+    MakeBinOpMembers(ExprOpUpdate, "//")
+};
+
 struct ExprConcatStrings : Expr
 {
     PosIdx pos;