diff --git a/docs/release_notes.rst b/docs/release_notes.rst
index be34248bb..fc16485ea 100644
--- a/docs/release_notes.rst
+++ b/docs/release_notes.rst
@@ -31,9 +31,11 @@ tagged yet.
 v15.4.0
 =======
 
--  Added new APIs to support offline editing of the final text. Specifically,
-   one can now generate hOCR files with OCRmyPDF, edit them with some other tool,
-   and then finalize the PDF.
+-  Added new experimental APIs to support offline editing of the final text.
+   Specifically, one can now generate hOCR files with OCRmyPDF, edit them with
+   some other tool, and then finalize the PDF. They are experimental and
+   subject to change, including details of how the working folder is used.
+   There is no command line interface.
 -  Code reorganization: executors, progress bars, initialization and setup.
 -  Fixed test coverage in cases where the coverage tool did not properly trace
    into threads or subprocesses. This code was still being tested but appeared
diff --git a/src/ocrmypdf/__init__.py b/src/ocrmypdf/__init__.py
index 5905aa58c..474619a61 100644
--- a/src/ocrmypdf/__init__.py
+++ b/src/ocrmypdf/__init__.py
@@ -14,7 +14,11 @@
     configure_debug_logging,
 )
 from ocrmypdf._version import PROGRAM_NAME, __version__
-from ocrmypdf.api import Verbosity, configure_logging, hocr_to_ocr_pdf, ocr, pdf_to_hocr
+from ocrmypdf.api import (
+    Verbosity,
+    configure_logging,
+    ocr,
+)
 from ocrmypdf.exceptions import (
     BadArgsError,
     DpiError,
@@ -45,7 +49,6 @@
     'ExitCode',
     'ExitCodeException',
     'helpers',
-    'hocr_to_ocr_pdf',
     'hocrtransform',
     'hookimpl',
     'InputFileError',
@@ -55,7 +58,6 @@
     'OrientationConfidence',
     'OutputFileAccessError',
     'PageContext',
-    'pdf_to_hocr',
     'pdfa',
     'PdfContext',
     'pdfinfo',
diff --git a/src/ocrmypdf/api.py b/src/ocrmypdf/api.py
index 98e22f680..9d78fe574 100644
--- a/src/ocrmypdf/api.py
+++ b/src/ocrmypdf/api.py
@@ -375,7 +375,7 @@ def ocr(  # noqa: D417
         return run_pipeline(options=options, plugin_manager=plugin_manager)
 
 
-def pdf_to_hocr(  # noqa: D417
+def _pdf_to_hocr(  # noqa: D417
     input_pdf: Path,
     output_folder: Path,
     *,
@@ -432,6 +432,8 @@ def pdf_to_hocr(  # noqa: D417
     For arguments not explicitly documented here, see documentation for the
     equivalent command line parameter.
 
+    This API is **experimental** and subject to change.
+
     Args:
         input_pdf: Input PDF file path.
         output_folder: Output folder path.
@@ -468,7 +470,7 @@ def pdf_to_hocr(  # noqa: D417
         return run_hocr_pipeline(options=options, plugin_manager=plugin_manager)
 
 
-def hocr_to_ocr_pdf(  # noqa: D417
+def _hocr_to_ocr_pdf(  # noqa: D417
     work_folder: Path,
     output_file: Path,
     *,
@@ -496,6 +498,8 @@ def hocr_to_ocr_pdf(  # noqa: D417
     For arguments not explicitly documented here, see documentation for the
     equivalent command line parameter.
 
+    This API is **experimental** and subject to change.
+
     Args:
         work_folder: Work folder path, as generated by :func:`pdf_to_hocr`.
         output_file: Output PDF file path.
@@ -543,8 +547,6 @@ def hocr_to_ocr_pdf(  # noqa: D417
     'get_parser',
     'get_plugin_manager',
     'ocr',
-    'pdf_to_hocr',
     'run_pipeline',
     'run_pipeline_cli',
-    'hocr_to_ocr_pdf',
 ]
diff --git a/tests/test_api.py b/tests/test_api.py
index 4e92c7194..540d4ac08 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -10,6 +10,7 @@
 from pdfminer.high_level import extract_text
 
 import ocrmypdf
+import ocrmypdf.api
 
 
 def test_language_list():
@@ -29,7 +30,7 @@ def test_stream_api(resources: Path):
 
 
 def test_hocr_api_multipage(resources: Path, outdir: Path, outpdf: Path):
-    ocrmypdf.pdf_to_hocr(
+    ocrmypdf.api._pdf_to_hocr(
         resources / 'multipage.pdf',
         outdir,
         language='eng',
@@ -40,12 +41,12 @@ def test_hocr_api_multipage(resources: Path, outdir: Path, outpdf: Path):
     assert (outdir / '000006_ocr_hocr.hocr').exists()
     assert not (outdir / '000004_ocr_hocr.hocr').exists()
 
-    ocrmypdf.hocr_to_ocr_pdf(outdir, outpdf)
+    ocrmypdf.api._hocr_to_ocr_pdf(outdir, outpdf)
     assert outpdf.exists()
 
 
 def test_hocr_to_pdf_api(resources: Path, outdir: Path, outpdf: Path):
-    ocrmypdf.pdf_to_hocr(
+    ocrmypdf.api._pdf_to_hocr(
         resources / 'ccitt.pdf',
         outdir,
         language='eng',
@@ -57,7 +58,7 @@ def test_hocr_to_pdf_api(resources: Path, outdir: Path, outpdf: Path):
     mangled = hocr.replace('the', 'hocr')
     (outdir / '000001_ocr_hocr.hocr').write_text(mangled, encoding='utf-8')
 
-    ocrmypdf.hocr_to_ocr_pdf(outdir, outpdf, optimize=0)
+    ocrmypdf.api._hocr_to_ocr_pdf(outdir, outpdf, optimize=0)
 
     text = extract_text(outpdf)
     assert 'hocr' in text and 'the' not in text