diff --git a/compiler/codegen_intrinsics_ecmascript.cpp b/compiler/codegen_intrinsics_ecmascript.cpp
index f9dd0b3549deca650bff4be102ac6484c07a3db6..5d8a499708bfc30b9ab63fc66615cb8b70e49bd0 100644
--- a/compiler/codegen_intrinsics_ecmascript.cpp
+++ b/compiler/codegen_intrinsics_ecmascript.cpp
@@ -182,7 +182,7 @@ void Codegen::StLexDyn(IntrinsicInst *inst, [[maybe_unused]] Reg dst, SRCREGS sr
     auto data = runtime->GetArrayDataOffset(arch);
     auto elem_size = runtime->GetTaggedArrayElementSize();
     auto start = runtime->GetLexicalEnvStartDataIndex();
-    constexpr size_t SLOT_INDEX = 2U;
+    constexpr size_t SLOT_INDEX = 1U;
     auto mem_ref = MemRef(lex_env_ptr, data + (start + inst->GetImms()[SLOT_INDEX]) * elem_size);
 
     ScopedTmpReg tmp_reg(enc, ConvertDataType(DataType::REFERENCE, arch));