diff --git a/src/browser/js/Env.zig b/src/browser/js/Env.zig
index e91ce4a1..bae6a8f0 100644
--- a/src/browser/js/Env.zig
+++ b/src/browser/js/Env.zig
@@ -296,7 +296,7 @@ pub fn createContext(self: *Env, page: *Page, params: ContextParams) !*Context {
         // it gets setup automatically as objects are created, but the Window
         // object already exists in v8 (it's the global) so we manually create
         // the mapping here.
-        const tao = try context_arena.create(@import("TaggedOpaque.zig"));
+        const tao = try params.identity_arena.create(@import("TaggedOpaque.zig"));
         tao.* = .{
             .value = @ptrCast(page.window),
             .prototype_chain = (&Window.JsApi.Meta.prototype_chain).ptr,
diff --git a/src/browser/js/Local.zig b/src/browser/js/Local.zig
index 4022a302..c9a3b880 100644
--- a/src/browser/js/Local.zig
+++ b/src/browser/js/Local.zig
@@ -244,7 +244,10 @@ pub fn mapZigInstanceToJs(self: *const Local, js_obj_handle: ?*const v8.Object,
                 // The TAO contains the pointer to our Zig instance as
                 // well as any meta data we'll need to use it later.
                 // See the TaggedOpaque struct for more details.
-                const tao = try context_arena.create(TaggedOpaque);
+                // Use identity_arena so TAOs survive context destruction. V8 objects
+                // are stored in identity_map (session-level) and may be referenced
+                // after their creating context is destroyed (e.g., via microtasks).
+                const tao = try ctx.identity_arena.create(TaggedOpaque);
                 tao.* = .{
                     .value = resolved.ptr,
                     .prototype_chain = resolved.prototype_chain.ptr,