diff --git a/webdriver/tests/bidi/emulation/set_locale_override/conftest.py b/webdriver/tests/bidi/emulation/set_locale_override/conftest.py
index e687010128a470..69623c821a865a 100644
--- a/webdriver/tests/bidi/emulation/set_locale_override/conftest.py
+++ b/webdriver/tests/bidi/emulation/set_locale_override/conftest.py
@@ -55,3 +55,23 @@ def another_locale(default_locale, some_locale):
     raise Exception(
         f"Unexpectedly could not find locale different from the default {default_locale} and {some_locale}"
     )
+
+
+@pytest_asyncio.fixture
+async def default_accept_language(get_fetch_headers, top_context):
+    """
+    Returns default value of `Accept-Language` header.
+    """
+    headers = await get_fetch_headers(top_context)
+    return headers["Accept-Language"] if "Accept-Language" in headers else None
+
+
+@pytest_asyncio.fixture
+async def assert_accept_language(assert_header_present):
+    """
+    Assert value of `Accept-Language` header.
+    """
+    async def assert_accept_language(context, value):
+        await assert_header_present(context, "Accept-Language", value)
+
+    return assert_accept_language
diff --git a/webdriver/tests/bidi/emulation/set_locale_override/locale.py b/webdriver/tests/bidi/emulation/set_locale_override/locale.py
index 3da7f62f520082..81a62f226cd9c4 100644
--- a/webdriver/tests/bidi/emulation/set_locale_override/locale.py
+++ b/webdriver/tests/bidi/emulation/set_locale_override/locale.py
@@ -4,8 +4,10 @@
 
 
 async def test_locale_set_override_and_reset(bidi_session, top_context,
-        get_current_locale, default_locale, some_locale, another_locale):
+        get_current_locale, default_locale, some_locale, another_locale,
+        assert_accept_language, default_accept_language):
     assert await get_current_locale(top_context) == default_locale
+    await assert_accept_language(top_context, default_accept_language)
 
     # Set locale override.
     await bidi_session.emulation.set_locale_override(
@@ -14,6 +16,7 @@ async def test_locale_set_override_and_reset(bidi_session, top_context,
     )
 
     assert await get_current_locale(top_context) == some_locale
+    await assert_accept_language(top_context, some_locale)
 
     # Set locale override.
     await bidi_session.emulation.set_locale_override(
@@ -22,6 +25,7 @@ async def test_locale_set_override_and_reset(bidi_session, top_context,
     )
 
     assert await get_current_locale(top_context) == another_locale
+    await assert_accept_language(top_context, another_locale)
 
     # Set locale override.
     await bidi_session.emulation.set_locale_override(
@@ -30,6 +34,7 @@ async def test_locale_set_override_and_reset(bidi_session, top_context,
     )
 
     assert await get_current_locale(top_context) == default_locale
+    await assert_accept_language(top_context, default_accept_language)
 
 
 @pytest.mark.parametrize("value", [
diff --git a/webdriver/tests/bidi/network/set_extra_headers/conftest.py b/webdriver/tests/bidi/network/set_extra_headers/conftest.py
index ce9462e9c038f9..d2bb72647b2b2d 100644
--- a/webdriver/tests/bidi/network/set_extra_headers/conftest.py
+++ b/webdriver/tests/bidi/network/set_extra_headers/conftest.py
@@ -62,21 +62,6 @@ async def get_navigation_headers(context):
     return get_navigation_headers
 
 
-@pytest_asyncio.fixture
-async def get_fetch_headers(bidi_session, url):
-    async def get_fetch_headers(context):
-        echo_link = url("webdriver/tests/support/http_handlers/headers_echo.py")
-        result = await bidi_session.script.evaluate(
-            expression=f"fetch('{echo_link}').then(r => r.text())",
-            target=ContextTarget(context["context"]),
-            await_promise=True,
-        )
-
-        return (json.JSONDecoder().decode(result["value"]))["headers"]
-
-    return get_fetch_headers
-
-
 @pytest_asyncio.fixture(params=["fetch", "navigation"])
 def get_headers_methods_invariant(request, get_fetch_headers,
         get_navigation_headers):
@@ -87,18 +72,6 @@ def get_headers_methods_invariant(request, get_fetch_headers,
     raise Exception(f"Unsupported getter {request.param}")
 
 
-@pytest_asyncio.fixture
-def assert_header_present(get_fetch_headers):
-    async def assert_header_present(context, header_name, header_value):
-        actual_headers = await get_fetch_headers(context)
-        assert header_name in actual_headers, \
-            f"header '{header_name}' should be present"
-        assert [header_value] == actual_headers[header_name], \
-            f"header '{header_name}' should have value '{header_value}'"
-
-    return assert_header_present
-
-
 @pytest_asyncio.fixture
 def assert_header_not_present(get_fetch_headers):
     async def assert_header_not_present(context, header_name):
diff --git a/webdriver/tests/support/fixtures_bidi.py b/webdriver/tests/support/fixtures_bidi.py
index 11f8df2b7fd3e2..0483b2da52832e 100644
--- a/webdriver/tests/support/fixtures_bidi.py
+++ b/webdriver/tests/support/fixtures_bidi.py
@@ -1111,3 +1111,31 @@ async def assert_file_dialog_not_canceled(context=None):
         cancel_event_future.cancel()
 
     yield assert_file_dialog_not_canceled
+
+
+@pytest_asyncio.fixture
+async def get_fetch_headers(bidi_session, url):
+    async def get_fetch_headers(context):
+        echo_link = url("webdriver/tests/support/http_handlers/headers_echo.py")
+        result = await bidi_session.script.evaluate(
+            expression=f"fetch('{echo_link}').then(r => r.text())",
+            target=ContextTarget(context["context"]),
+            await_promise=True,
+        )
+
+        return (json.JSONDecoder().decode(result["value"]))["headers"]
+
+    return get_fetch_headers
+
+
+@pytest_asyncio.fixture
+def assert_header_present(get_fetch_headers):
+    async def assert_header_present(context, header_name, header_value):
+        actual_headers = await get_fetch_headers(context)
+        assert header_name in actual_headers, \
+            f"header '{header_name}' should be present"
+        assert [header_value] == actual_headers[header_name], \
+            f"header '{header_name}' should have value '{header_value}'"
+
+    return assert_header_present
+