diff --git a/VM/src/lobject.cpp b/VM/src/lobject.cpp
index 640bd96e..081e3314 100644
--- a/VM/src/lobject.cpp
+++ b/VM/src/lobject.cpp
@@ -48,7 +48,7 @@ int luaO_rawequalObj(const TValue* t1, const TValue* t2)
         case LUA_TBOOLEAN:
             return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
-            return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
+            return pvalue(t1) == pvalue(t2) && (!FFlag::TaggedLuData || lightuserdatatag(t1) == lightuserdatatag(t2));
         default:
             LUAU_ASSERT(iscollectable(t1));
             return gcvalue(t1) == gcvalue(t2);
@@ -71,7 +71,7 @@ int luaO_rawequalKey(const TKey* t1, const TValue* t2)
         case LUA_TBOOLEAN:
             return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
-            return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
+            return pvalue(t1) == pvalue(t2) && (!FFlag::TaggedLuData || lightuserdatatag(t1) == lightuserdatatag(t2));
         default:
             LUAU_ASSERT(iscollectable(t1));
             return gcvalue(t1) == gcvalue(t2);
diff --git a/VM/src/lobject.h b/VM/src/lobject.h
index 70a51923..d236f7e4 100644
--- a/VM/src/lobject.h
+++ b/VM/src/lobject.h
@@ -498,3 +498,5 @@ LUAI_FUNC int luaO_str2d(const char* s, double* result);
 LUAI_FUNC const char* luaO_pushvfstring(lua_State* L, const char* fmt, va_list argp);
 LUAI_FUNC const char* luaO_pushfstring(lua_State* L, const char* fmt, ...);
 LUAI_FUNC const char* luaO_chunkid(char* buf, size_t buflen, const char* source, size_t srclen);
+
+LUAU_FASTFLAG(TaggedLuData)
diff --git a/VM/src/ltm.cpp b/VM/src/ltm.cpp
index 09c3d824..3a9fddaa 100644
--- a/VM/src/ltm.cpp
+++ b/VM/src/ltm.cpp
@@ -129,7 +129,7 @@ const TString* luaT_objtypenamestr(lua_State* L, const TValue* o)
         if (ttisstring(type))
             return tsvalue(type);
     }
-    else if (ttislightuserdata(o))
+    else if (FFlag::TaggedLuData && ttislightuserdata(o))
     {
         int tag = lightuserdatatag(o);
 
diff --git a/VM/src/lvmexecute.cpp b/VM/src/lvmexecute.cpp
index 14780ba1..1c77fa14 100644
--- a/VM/src/lvmexecute.cpp
+++ b/VM/src/lvmexecute.cpp
@@ -135,6 +135,8 @@
 // Does VM support native execution via ExecutionCallbacks? We mostly assume it does but keep the define to make it easy to quantify the cost.
 #define VM_HAS_NATIVE 1
 
+LUAU_FASTFLAGVARIABLE(TaggedLuData, false)
+
 LUAU_NOINLINE void luau_callhook(lua_State* L, lua_Hook hook, void* userdata)
 {
     ptrdiff_t base = savestack(L, L->base);
@@ -1110,7 +1112,7 @@ reentry:
                         VM_NEXT();
 
                     case LUA_TLIGHTUSERDATA:
-                        pc += (pvalue(ra) == pvalue(rb) && lightuserdatatag(ra) == lightuserdatatag(rb)) ? LUAU_INSN_D(insn) : 1;
+                        pc += (pvalue(ra) == pvalue(rb) && (!FFlag::TaggedLuData || lightuserdatatag(ra) == lightuserdatatag(rb))) ? LUAU_INSN_D(insn) : 1;
                         LUAU_ASSERT(unsigned(pc - cl->l.p->code) < unsigned(cl->l.p->sizecode));
                         VM_NEXT();
 
@@ -1225,7 +1227,7 @@ reentry:
                         VM_NEXT();
 
                     case LUA_TLIGHTUSERDATA:
-                        pc += (pvalue(ra) != pvalue(rb) || lightuserdatatag(ra) != lightuserdatatag(rb)) ? LUAU_INSN_D(insn) : 1;
+                        pc += (pvalue(ra) != pvalue(rb) || (FFlag::TaggedLuData && lightuserdatatag(ra) != lightuserdatatag(rb))) ? LUAU_INSN_D(insn) : 1;
                         LUAU_ASSERT(unsigned(pc - cl->l.p->code) < unsigned(cl->l.p->sizecode));
                         VM_NEXT();
 
diff --git a/VM/src/lvmutils.cpp b/VM/src/lvmutils.cpp
index 4db8bba7..851d778c 100644
--- a/VM/src/lvmutils.cpp
+++ b/VM/src/lvmutils.cpp
@@ -288,7 +288,7 @@ int luaV_equalval(lua_State* L, const TValue* t1, const TValue* t2)
     case LUA_TBOOLEAN:
         return bvalue(t1) == bvalue(t2); // true must be 1 !!
     case LUA_TLIGHTUSERDATA:
-        return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
+        return pvalue(t1) == pvalue(t2) && (!FFlag::TaggedLuData || lightuserdatatag(t1) == lightuserdatatag(t2));
     case LUA_TUSERDATA:
     {
         tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable, TM_EQ);
diff --git a/tests/Conformance.test.cpp b/tests/Conformance.test.cpp
index e3eb4cbb..7360ecb3 100644
--- a/tests/Conformance.test.cpp
+++ b/tests/Conformance.test.cpp
@@ -32,6 +32,7 @@ LUAU_FASTFLAG(LuauBufferDefinitions);
 LUAU_FASTFLAG(LuauCodeGenFixByteLower);
 LUAU_FASTFLAG(LuauCompileBufferAnnotation);
 LUAU_FASTFLAG(LuauLoopInterruptFix);
+LUAU_FASTFLAG(TaggedLuData);
 LUAU_DYNAMIC_FASTFLAG(LuauStricterUtf8);
 
 static lua_CompileOptions defaultOptions()
@@ -1701,6 +1702,8 @@ TEST_CASE("UserdataApi")
 
 TEST_CASE("LightuserdataApi")
 {
+    ScopedFastFlag taggedLuData{FFlag::TaggedLuData, true};
+
     StateRef globalState(luaL_newstate(), lua_close);
     lua_State* L = globalState.get();