diff --git a/common.gypi b/common.gypi
index 4589f515178093..d2cd306aadfebf 100644
--- a/common.gypi
+++ b/common.gypi
@@ -36,7 +36,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.25',
+    'v8_embedder_string': '-node.15',
 
     ##### V8 defaults for Node.js #####
 
diff --git a/deps/v8/src/builtins/riscv/builtins-riscv.cc b/deps/v8/src/builtins/riscv/builtins-riscv.cc
index 3404562785991c..d6091434b9b0ad 100644
--- a/deps/v8/src/builtins/riscv/builtins-riscv.cc
+++ b/deps/v8/src/builtins/riscv/builtins-riscv.cc
@@ -1512,7 +1512,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   // Set the return address to the correct point in the interpreter entry
   // trampoline.
   Label builtin_trampoline, trampoline_loaded;
-  Smi interpreter_entry_return_pc_offset(
+  Tagged<Smi> interpreter_entry_return_pc_offset(
       masm->isolate()->heap()->interpreter_entry_return_pc_offset());
   DCHECK_NE(interpreter_entry_return_pc_offset, Smi::zero());
 
diff --git a/deps/v8/src/codegen/riscv/assembler-riscv-inl.h b/deps/v8/src/codegen/riscv/assembler-riscv-inl.h
index 55f191e6afe76e..ca6d641e2c94ed 100644
--- a/deps/v8/src/codegen/riscv/assembler-riscv-inl.h
+++ b/deps/v8/src/codegen/riscv/assembler-riscv-inl.h
@@ -128,9 +128,9 @@ Handle<HeapObject> Assembler::compressed_embedded_object_handle_at(
 }
 
 void Assembler::deserialization_set_special_target_at(
-    Address instruction_payload, Code code, Address target) {
+    Address instruction_payload, Tagged<Code> code, Address target) {
   set_target_address_at(instruction_payload,
-                        !code.is_null() ? code.constant_pool() : kNullAddress,
+                        !code.is_null() ? code->constant_pool() : kNullAddress,
                         target);
 }
 
@@ -159,12 +159,13 @@ void Assembler::deserialization_set_target_internal_reference_at(
   }
 }
 
-HeapObject RelocInfo::target_object(PtrComprCageBase cage_base) {
+Tagged<HeapObject> RelocInfo::target_object(PtrComprCageBase cage_base) {
   DCHECK(IsCodeTarget(rmode_) || IsEmbeddedObjectMode(rmode_));
   if (IsCompressedEmbeddedObject(rmode_)) {
-    return HeapObject::cast(Object(V8HeapCompressionScheme::DecompressTagged(
-        cage_base,
-        Assembler::target_compressed_address_at(pc_, constant_pool_))));
+    return HeapObject::cast(
+        Tagged<Object>(V8HeapCompressionScheme::DecompressTagged(
+            cage_base,
+            Assembler::target_compressed_address_at(pc_, constant_pool_))));
   } else {
     return HeapObject::cast(
         Object(Assembler::target_address_at(pc_, constant_pool_)));
@@ -186,8 +187,7 @@ Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
   }
 }
 
-void RelocInfo::set_target_object(Heap* heap, HeapObject target,
-                                  WriteBarrierMode write_barrier_mode,
+void RelocInfo::set_target_object(Tagged<HeapObject> target,
                                   ICacheFlushMode icache_flush_mode) {
   DCHECK(IsCodeTarget(rmode_) || IsEmbeddedObjectMode(rmode_));
   if (IsCompressedEmbeddedObject(rmode_)) {
diff --git a/deps/v8/src/codegen/riscv/assembler-riscv.h b/deps/v8/src/codegen/riscv/assembler-riscv.h
index ed222b52d69279..bcd5a62d324ee5 100644
--- a/deps/v8/src/codegen/riscv/assembler-riscv.h
+++ b/deps/v8/src/codegen/riscv/assembler-riscv.h
@@ -286,7 +286,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase,
   // This is for calls and branches within generated code.  The serializer
   // has already deserialized the lui/ori instructions etc.
   inline static void deserialization_set_special_target_at(Address location,
-                                                           Code code,
+                                                           Tagged<Code> code,
                                                            Address target);
 
   // Get the size of the special target encoded at 'instruction_payload'.
diff --git a/deps/v8/src/execution/riscv/simulator-riscv.cc b/deps/v8/src/execution/riscv/simulator-riscv.cc
index 9582db489638a3..052a2d67dd7e44 100644
--- a/deps/v8/src/execution/riscv/simulator-riscv.cc
+++ b/deps/v8/src/execution/riscv/simulator-riscv.cc
@@ -1781,7 +1781,7 @@ void RiscvDebugger::Debug() {
           sreg_t value;
           StdoutStream os;
           if (GetValue(arg1, &value)) {
-            Object obj(value);
+            Tagged<Object> obj(value);
             os << arg1 << ": \n";
 #ifdef DEBUG
             obj.Print(os);
@@ -1830,7 +1830,7 @@ void RiscvDebugger::Debug() {
           PrintF("  0x%012" PRIxPTR " :  0x%016" REGIx_FORMAT
                  "  %14" REGId_FORMAT " ",
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
-          Object obj(*cur);
+          Tagged<Object> obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
           if (obj.IsSmi() ||
               IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
@@ -4692,7 +4692,7 @@ bool Simulator::DecodeRvvVS() {
 Builtin Simulator::LookUp(Address pc) {
   for (Builtin builtin = Builtins::kFirst; builtin <= Builtins::kLast;
        ++builtin) {
-    if (builtins_.code(builtin).contains(isolate_, pc)) return builtin;
+    if (builtins_.code(builtin)->contains(isolate_, pc)) return builtin;
   }
   return Builtin::kNoBuiltinId;
 }
@@ -4709,7 +4709,7 @@ void Simulator::DecodeRVIType() {
         if (builtin != Builtin::kNoBuiltinId) {
           auto code = builtins_.code(builtin);
           if ((rs1_reg() != ra || imm12() != 0)) {
-            if ((Address)get_pc() == code.InstructionStart()) {
+            if ((Address)get_pc() == code->instruction_start()) {
               sreg_t arg0 = get_register(a0);
               sreg_t arg1 = get_register(a1);
               sreg_t arg2 = get_register(a2);
diff --git a/deps/v8/src/regexp/riscv/regexp-macro-assembler-riscv.cc b/deps/v8/src/regexp/riscv/regexp-macro-assembler-riscv.cc
index 4063b4b3d21948..72f89767eb3489 100644
--- a/deps/v8/src/regexp/riscv/regexp-macro-assembler-riscv.cc
+++ b/deps/v8/src/regexp/riscv/regexp-macro-assembler-riscv.cc
@@ -1211,7 +1211,7 @@ static T* frame_entry_address(Address re_frame, int frame_offset) {
 int64_t RegExpMacroAssemblerRISCV::CheckStackGuardState(Address* return_address,
                                                         Address raw_code,
                                                         Address re_frame) {
-  InstructionStream re_code = InstructionStream::cast(Object(raw_code));
+  Tagged<InstructionStream> re_code = InstructionStream::cast(Object(raw_code));
   return NativeRegExpMacroAssembler::CheckStackGuardState(
       frame_entry<Isolate*>(re_frame, kIsolateOffset),
       static_cast<int>(frame_entry<int64_t>(re_frame, kStartIndexOffset)),