diff --git a/src/browser/browser.zig b/src/browser/browser.zig
index cc153870..c421498c 100644
--- a/src/browser/browser.zig
+++ b/src/browser/browser.zig
@@ -215,7 +215,9 @@ pub const Page = struct {
     }
 
     // start js env.
-    pub fn start(self: *Page) !void {
+    // - auxData: extra data forwarded to the Inspector
+    // see Inspector.contextCreated
+    pub fn start(self: *Page, auxData: ?[]const u8) !void {
         // start JS env
         log.debug("start js env", .{});
         try self.session.env.start();
@@ -226,6 +228,15 @@ pub const Page = struct {
         // add global objects
         log.debug("setup global env", .{});
         try self.session.env.bindGlobal(&self.session.window);
+
+        // load polyfills
+        try polyfill.load(self.arena.allocator(), self.session.env);
+
+        // inspector
+        if (self.session.inspector) |inspector| {
+            log.debug("inspector context created", .{});
+            inspector.contextCreated(self.session.env, "", self.origin orelse "://", auxData);
+        }
     }
 
     // reset js env and mem arena.
@@ -387,9 +398,6 @@ pub const Page = struct {
 
         // https://html.spec.whatwg.org/#read-html
 
-        // load polyfills
-        try polyfill.load(alloc, self.session.env);
-
         // inspector
         if (self.session.inspector) |inspector| {
             inspector.contextCreated(self.session.env, "", self.origin.?, auxData);
diff --git a/src/cdp/target.zig b/src/cdp/target.zig
index ea8aac87..e3120379 100644
--- a/src/cdp/target.zig
+++ b/src/cdp/target.zig
@@ -351,8 +351,16 @@ fn createTarget(
 
     // create the page
     const p = try ctx.browser.session.createPage();
+    ctx.state.executionContextId += 1;
     // start the js env
-    try p.start();
+    const auxData = try std.fmt.allocPrint(
+        alloc,
+        // NOTE: we assume this is the default web page
+        "{{\"isDefault\":true,\"type\":\"default\",\"frameId\":\"{s}\"}}",
+        .{ctx.state.frameID},
+    );
+    defer alloc.free(auxData);
+    try p.start(auxData);
 
     // send targetCreated event
     const created = TargetCreated{
diff --git a/src/main.zig b/src/main.zig
index 787f1501..e4da1df2 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -326,7 +326,7 @@ pub fn main() !void {
 
             // page
             const page = try browser.session.createPage();
-            try page.start();
+            try page.start(null);
             defer page.end();
 
             _ = page.navigate(opts.url, null) catch |err| switch (err) {