diff --git a/js/src/irregexp/imported/regexp-bytecodes-inl.h b/js/src/irregexp/imported/regexp-bytecodes-inl.h
--- a/imported/regexp-bytecodes-inl.h
+++ b/imported/regexp-bytecodes-inl.h
@@ -156,8 +156,7 @@
 #define DECLARE_OPERAND_NAMES(CamelName, OpNames, OpTypes, ...)           \
   template <>                                                             \
   struct BytecodeOperandNames<Bytecode::k##CamelName> {                   \
-    enum class Operand { UNPAREN(OpNames) };                              \
-    using enum Operand;                                                   \
+    enum Operand { UNPAREN(OpNames) };                                    \
     static constexpr size_t kCount = detail::CountOf<UNPAREN(OpNames)>(); \
     static constexpr auto kNames = detail::SplitNames<kCount>(#OpNames);  \
     static constexpr std::string_view Name(Operand op) {                  \
@@ -293,8 +292,6 @@
       : public detail::BytecodeOperandsBase<PACK_OPTIONAL( \
             Bytecode::k##CamelName, UNPAREN(OpTypes))>,    \
         public AllStatic {                                 \
-   public:                                                 \
-    using enum Operand;                                    \
   };

 REGEXP_BYTECODE_LIST(DECLARE_OPERANDS)