diff --git a/src/unstract/llmwhisperer/client_v2.py b/src/unstract/llmwhisperer/client_v2.py
index cf97f4b..6952df0 100644
--- a/src/unstract/llmwhisperer/client_v2.py
+++ b/src/unstract/llmwhisperer/client_v2.py
@@ -517,7 +517,9 @@ def whisper(
         params = {
             "mode": mode,
             "output_mode": output_mode,
+            # Both spellings are sent: services older than v2.64.2 read only the misspelled one
             "page_separator": page_separator,
+            "page_seperator": page_separator,
             "pages_to_extract": pages_to_extract,
             "median_filter_size": median_filter_size,
             "gaussian_blur_radius": gaussian_blur_radius,
diff --git a/tests/unit/client_v2_test.py b/tests/unit/client_v2_test.py
index 9f7a7fa..4d03e50 100644
--- a/tests/unit/client_v2_test.py
+++ b/tests/unit/client_v2_test.py
@@ -209,11 +209,21 @@ def test_whisper_sends_corrected_param_names(mocker: MockerFixture, client_v2: L
     assert query["page_separator"] == ["---"]
     assert query["line_splitter_strategy"] == ["mid-priority"]
     assert query["file_name"] == ["invoice.pdf"]
-    assert "page_seperator" not in query
     assert "line_spitter_strategy" not in query
     assert "filename" not in query
 
 
+@pytest.mark.parametrize(("kwargs", "expected"), [({}, "<<<"), ({"page_separator": "---"}, "---")])
+def test_whisper_sends_page_separator_under_both_spellings(
+    mocker: MockerFixture, client_v2: LLMWhispererClientV2, kwargs: dict[str, str], expected: str
+) -> None:
+    """Older services read only the misspelled key, so both carry the value."""
+    query = _whisper_query(mocker, client_v2, **kwargs)
+
+    assert query["page_separator"] == [expected]
+    assert query["page_seperator"] == [expected]
+
+
 def test_whisper_defaults_when_no_param_passed(mocker: MockerFixture, client_v2: LLMWhispererClientV2) -> None:
     """Omitting the renamed params keeps the previous defaults."""
     query = _whisper_query(mocker, client_v2)
@@ -224,11 +234,12 @@ def test_whisper_defaults_when_no_param_passed(mocker: MockerFixture, client_v2:
 
 
 def test_whisper_deprecated_page_seperator_is_forwarded(mocker: MockerFixture, client_v2: LLMWhispererClientV2) -> None:
-    """page_seperator still applies, under the corrected name."""
+    """page_seperator still applies, under both spellings on the wire."""
     with pytest.warns(DeprecationWarning, match="page_separator"):
         query = _whisper_query(mocker, client_v2, page_seperator="---")
 
     assert query["page_separator"] == ["---"]
+    assert query["page_seperator"] == ["---"]
 
 
 def test_whisper_deprecated_filename_is_forwarded(mocker: MockerFixture, client_v2: LLMWhispererClientV2) -> None: