diff --git a/pyproject.toml b/pyproject.toml
index 773afa47..76aeceb8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,7 +12,6 @@ readme = "README.md"
 license = "MPL-2.0"
 requires-python = ">=3.11"
 dependencies = [
-  "deprecation>=2.1.0",
   "fpdf2>=2.8.0",
   "img2pdf>=0.5",
   "packaging>=20",
@@ -24,6 +23,7 @@ dependencies = [
   "pydantic>=2.12.5",
   "pypdfium2>=5.0.0",
   "rich>=13",
+  "typing-extensions>=4.12; python_version < '3.13'",
   "uharfbuzz>=0.53.2",
 ]
 authors = [{ name = "James R. Barlow", email = "james@purplerock.ca" }]
@@ -101,15 +101,24 @@ filterwarnings = [
 
 [[tool.mypy.overrides]]
 module = [
-  'pluggy',
   'img2pdf',
   'pdfminer.*',
   'reportlab.*',
   'fitz',
   'libxmp.utils',
+  'pypdfium2',
+  'uharfbuzz',
+  'pi_heif',
 ]
 ignore_missing_imports = true
 
+[[tool.mypy.overrides]]
+# Test functions are not required to annotate their return type (almost
+# always None); it's a low-value hint that would just be noise here.
+module = 'tests.*'
+disallow_untyped_defs = false
+disallow_incomplete_defs = false
+
 [tool.ruff]
 target-version = "py311"
 exclude = ["src/ocrmypdf/_version.py"] # Autogenerated
diff --git a/src/ocrmypdf/_exec/ghostscript.py b/src/ocrmypdf/_exec/ghostscript.py
index d9fc9dc1..4dc98d72 100644
--- a/src/ocrmypdf/_exec/ghostscript.py
+++ b/src/ocrmypdf/_exec/ghostscript.py
@@ -105,8 +105,8 @@ def _gs_devicen_reported(stream) -> bool:
 
 
 def rasterize_pdf(
-    input_file: os.PathLike,
-    output_file: os.PathLike,
+    input_file: Path,
+    output_file: Path,
     *,
     raster_device: GhostscriptRasterDevice,
     raster_dpi: Resolution,
@@ -288,7 +288,7 @@ class GhostscriptFollower:
 
 def generate_pdfa(
     pdf_pages,
-    output_file: os.PathLike,
+    output_file: Path,
     *,
     compression: str,
     color_conversion_strategy: str,
diff --git a/src/ocrmypdf/_options.py b/src/ocrmypdf/_options.py
index 3e956135..9018eabb 100644
--- a/src/ocrmypdf/_options.py
+++ b/src/ocrmypdf/_options.py
@@ -29,7 +29,7 @@ log = logging.getLogger(__name__)
 
 # Module-level registry for plugin option models
 # This is populated by setup_plugin_infrastructure() after plugins are loaded
-_plugin_option_models: dict[str, type] = {}
+_plugin_option_models: dict[str, type[BaseModel]] = {}
 
 PathOrIO = BinaryIO | IOBase | Path | str | bytes
 
@@ -209,7 +209,6 @@ class OcrOptions(BaseModel):
     optimize: int = 1
     jpg_quality: int | None = None
     png_quality: int | None = None
-    jbig2_threshold: float = 0.85
 
     # Compatibility alias for plugins that expect jpeg_quality
     @property
@@ -576,7 +575,7 @@ class OcrOptions(BaseModel):
     )
 
     @classmethod
-    def register_plugin_models(cls, models: dict[str, type]) -> None:
+    def register_plugin_models(cls, models: dict[str, type[BaseModel]]) -> None:
         """Register plugin option model classes for nested access.
 
         Args:
diff --git a/src/ocrmypdf/_pipeline.py b/src/ocrmypdf/_pipeline.py
index 2da12769..0f568a39 100644
--- a/src/ocrmypdf/_pipeline.py
+++ b/src/ocrmypdf/_pipeline.py
@@ -28,7 +28,7 @@ from ocrmypdf._concurrent import Executor
 from ocrmypdf._exec import unpaper
 from ocrmypdf._jobcontext import PageContext, PdfContext
 from ocrmypdf._metadata import repair_docinfo_nuls
-from ocrmypdf._options import OcrOptions, ProcessingMode, TaggedPdfMode
+from ocrmypdf._options import OcrOptions, PathOrIO, ProcessingMode, TaggedPdfMode
 from ocrmypdf._pageboxes import log_box_repairs, repair_page_boxes
 from ocrmypdf._stdoutprotect import get_protected_stdout_fd
 from ocrmypdf.exceptions import (
@@ -1284,7 +1284,8 @@ def enumerate_compress_ranges(
         A tuple containing a range of indices and the corresponding element.
         If the element is None, the range represents a skipped range of indices.
     """
-    skipped_from, index = None, None
+    skipped_from: int | None = None
+    index: int | None = None
     for index, txt_file in enumerate(iterable):
         index += 1
         if txt_file:
@@ -1296,6 +1297,9 @@ def enumerate_compress_ranges(
             if skipped_from is None:
                 skipped_from = index
     if skipped_from is not None:
+        # skipped_from can only be set inside the loop above, so the loop
+        # must have run at least once and index is guaranteed to be an int.
+        assert index is not None
         yield (skipped_from, index), None
 
 
@@ -1322,18 +1326,12 @@ def merge_sidecars(txt_files: Iterable[Path | None], context: PdfContext) -> Pat
     return output_file
 
 
-def copy_final(
-    input_file: Path, output_file: str | Path | BinaryIO, original_file: Path | None
-) -> None:
+def copy_final(input_file: Path, output_file: PathOrIO) -> None:
     """Copy the final temporary file to the output destination.
 
     Args:
-        input_file (Path): The intermediate input file to copy.
-        output_file (str | Path | BinaryIO): The output file to copy to.
-        original_file: The original file to copy attributes from.
-
-    Returns:
-        None
+        input_file: The intermediate input file to copy.
+        output_file: The output file to copy to.
     """
     log.debug('%s -> %s', input_file, output_file)
     with input_file.open('rb') as input_stream:
@@ -1359,5 +1357,7 @@ def copy_final(
             # At this point we overwrite the output_file specified by the user
             # use copyfileobj because then we use open() to create the file and
             # get the appropriate umask, ownership, etc.
+            # The `hasattr` check above already ruled out stream-like objects.
+            assert isinstance(output_file, str | bytes | os.PathLike)
             with open(output_file, 'w+b') as output_stream:
                 copyfileobj(input_stream, output_stream)
diff --git a/src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py b/src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py
index 750901f3..a09dd259 100644
--- a/src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py
+++ b/src/ocrmypdf/_pipelines/hocr_to_ocr_pdf.py
@@ -98,8 +98,8 @@ def exec_hocr_to_ocr_pdf(context: PdfContext, executor: Executor) -> Sequence[st
         log.info("Postprocessing...")
         pdf, messages = postprocess(pdf, context, executor)
 
-        # Copy PDF file to destination (we don't know the input PDF file name)
-        copy_final(pdf, options.output_file, None)
+        # Copy PDF file to destination
+        copy_final(pdf, options.output_file)
     return messages
 
 
@@ -109,6 +109,9 @@ def run_hocr_to_ocr_pdf_pipeline(
     plugin_manager: OcrmypdfPluginManager,
 ) -> ExitCode:
     """Run pipeline to convert hOCR to final output PDF."""
+    # The _hocr_to_ocr_pdf() API requires work_folder: Path and stores it on
+    # options before this pipeline runs, so it is always set at this point.
+    assert options.work_folder is not None
     with manage_work_folder(
         work_folder=options.work_folder, retain=True, print_location=False
     ) as work_folder:
diff --git a/src/ocrmypdf/_pipelines/ocr.py b/src/ocrmypdf/_pipelines/ocr.py
index dd0288e7..f15f2ad6 100644
--- a/src/ocrmypdf/_pipelines/ocr.py
+++ b/src/ocrmypdf/_pipelines/ocr.py
@@ -145,7 +145,7 @@ def exec_concurrent(context: PdfContext, executor: Executor) -> Sequence[str]:
     if options.sidecar:
         text = merge_sidecars(sidecars, context)
         # Copy text file to destination
-        copy_final(text, options.sidecar, options.input_file)
+        copy_final(text, options.sidecar)
 
     # Merge layers to one single pdf
     pdf = ocrgraft.finalize()
@@ -157,7 +157,7 @@ def exec_concurrent(context: PdfContext, executor: Executor) -> Sequence[str]:
         pdf, messages = postprocess(pdf, context, executor)
 
         # Copy PDF file to destination
-        copy_final(pdf, options.output_file, options.input_file)
+        copy_final(pdf, options.output_file)
     return messages
 
 
diff --git a/src/ocrmypdf/_pipelines/pdf_to_hocr.py b/src/ocrmypdf/_pipelines/pdf_to_hocr.py
index b63f67d9..eca8d703 100644
--- a/src/ocrmypdf/_pipelines/pdf_to_hocr.py
+++ b/src/ocrmypdf/_pipelines/pdf_to_hocr.py
@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import logging
 import logging.handlers
+import os
 import shutil
 from functools import partial
 
@@ -91,6 +92,9 @@ def run_hocr_pipeline(
     """Run pipeline to output hOCR."""
     if options.output_folder is None:
         raise ValueError("output_folder must be specified for hOCR pipeline")
+    # This pipeline is only reachable via the _pdf_to_hocr() API, which
+    # declares input_pdf: Path - streams and raw bytes paths are not supported.
+    assert isinstance(options.input_file, str | os.PathLike)
     with manage_work_folder(
         work_folder=options.output_folder, retain=True, print_location=False
     ) as work_folder:
@@ -100,9 +104,7 @@ def run_hocr_pipeline(
 
         # Gather pdfinfo and create context
         pdfinfo = do_get_pdfinfo(origin_pdf, executor, options)
-        context = PdfContext(
-            options, work_folder, options.input_file, pdfinfo, plugin_manager
-        )
+        context = PdfContext(options, work_folder, origin_pdf, pdfinfo, plugin_manager)
         # Validate options are okay for this pdf
         validate_pdfinfo_options(context)
         exec_pdf_to_hocr(context, executor)
diff --git a/src/ocrmypdf/_plugin_manager.py b/src/ocrmypdf/_plugin_manager.py
index f6f1abb7..c128766e 100644
--- a/src/ocrmypdf/_plugin_manager.py
+++ b/src/ocrmypdf/_plugin_manager.py
@@ -21,6 +21,7 @@ from pydantic import BaseModel
 import ocrmypdf.builtin_plugins
 from ocrmypdf import Executor, PdfContext, pluginspec
 from ocrmypdf._options import OcrOptions
+from ocrmypdf._plugin_registry import PluginOptionRegistry
 from ocrmypdf._progressbar import ProgressBar
 from ocrmypdf.helpers import Resolution
 from ocrmypdf.pluginspec import OcrEngine
@@ -53,10 +54,11 @@ class OcrmypdfPluginManager:
         self._plugins = plugins
         self._builtins = builtins
         self._pm = pluggy.PluginManager(*args, **kwargs)
+        self._option_registry: PluginOptionRegistry | None = None
         self._setup_plugins()
 
     @property
-    def pluggy(self) -> pluggy.PluginManager:
+    def pluggy_manager(self) -> pluggy.PluginManager:
         """Access the underlying pluggy.PluginManager for advanced use cases.
 
         This is useful for plugins that need to call methods like set_blocked()
diff --git a/src/ocrmypdf/_validation.py b/src/ocrmypdf/_validation.py
index 1f3c6116..1bfeb278 100644
--- a/src/ocrmypdf/_validation.py
+++ b/src/ocrmypdf/_validation.py
@@ -10,8 +10,10 @@ import logging
 import os
 import sys
 from collections.abc import Sequence
+from collections.abc import Set as AbstractSet
 from pathlib import Path
 from shutil import copyfileobj
+from typing import BinaryIO, cast
 
 import pikepdf
 
@@ -48,7 +50,7 @@ def check_platform() -> None:
 
 
 def check_options_languages(
-    options: OcrOptions, ocr_engine_languages: list[str]
+    options: OcrOptions, ocr_engine_languages: AbstractSet[str]
 ) -> None:
     # Check for blocked languages first, before checking if they're installed
     DENIED_LANGUAGES = {'equ', 'osd'}
@@ -92,7 +94,15 @@ def check_options_sidecar(options: OcrOptions) -> None:
             raise BadArgsError(
                 "--sidecar filename needed when output file is /dev/null or NUL."
             )
-        options.sidecar = options.output_file + '.txt'
+        elif not isinstance(options.output_file, str | Path):
+            # The '\0' sentinel is only ever set by the CLI, which always
+            # supplies output_file as a plain path - not a stream. If this
+            # somehow fires, the caller mixed a CLI-only sentinel with the
+            # stream-based API.
+            raise BadArgsError(
+                "--sidecar filename needed when output file is not a path."
+            )
+        options.sidecar = os.fspath(options.output_file) + '.txt'
     if options.sidecar == options.input_file or options.sidecar == options.output_file:
         raise BadArgsError(
             "--sidecar file must be different from the input and output files"
@@ -194,20 +204,24 @@ def create_input_file(options: OcrOptions, work_folder: Path) -> tuple[Path, str
             copyfileobj(sys.stdin.buffer, stream_buffer)
         return target, "stdin"
     elif hasattr(options.input_file, 'readable'):
-        if not options.input_file.readable():
+        input_stream = cast(BinaryIO, options.input_file)
+        if not input_stream.readable():
             raise InputFileError("Input file stream is not readable")
         log.info('reading file from input stream')
         target = work_folder / 'stream'
         with open(target, 'wb') as stream_buffer:
-            copyfileobj(options.input_file, stream_buffer)
+            copyfileobj(input_stream, stream_buffer)
         return target, "stream"
     else:
+        # The branches above already ruled out the stdin sentinel and
+        # stream-like objects, so this must be a filesystem path.
+        assert isinstance(options.input_file, str | bytes | os.PathLike)
         try:
             target = work_folder / 'origin'
             safe_symlink(options.input_file, target)
-            return target, os.fspath(options.input_file)
+            return target, os.fsdecode(options.input_file)
         except FileNotFoundError as e:
-            msg = f"File not found - {options.input_file}"
+            msg = f"File not found - {os.fsdecode(options.input_file)}"
             if running_in_docker():  # pragma: no cover
                 msg += (
                     "\nDocker cannot access your working directory unless you "
@@ -249,7 +263,8 @@ def check_requested_output_file(options: OcrOptions) -> None:
             raise OutputFileAccessError("Output stream is not writable")
     elif not is_file_writable(options.output_file):
         raise OutputFileAccessError(
-            f"Output file location ({options.output_file}) is not a writable file."
+            f"Output file location ({os.fsdecode(options.output_file)}) is not a "
+            "writable file."
         )
 
     if (
@@ -259,7 +274,7 @@ def check_requested_output_file(options: OcrOptions) -> None:
         and Path(str(options.output_file)).exists()
     ):
         raise OutputFileAccessError(
-            f"Output file already exists: {options.output_file}\n"
+            f"Output file already exists: {os.fsdecode(options.output_file)}\n"
             "To overwrite it, omit the --no-overwrite / -n option."
         )
 
diff --git a/src/ocrmypdf/_validation_coordinator.py b/src/ocrmypdf/_validation_coordinator.py
index d5440475..1d4ae23f 100644
--- a/src/ocrmypdf/_validation_coordinator.py
+++ b/src/ocrmypdf/_validation_coordinator.py
@@ -10,9 +10,8 @@ import os
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    import pluggy
-
     from ocrmypdf._options import OcrOptions
+    from ocrmypdf._plugin_manager import OcrmypdfPluginManager
 
 log = logging.getLogger(__name__)
 
@@ -20,9 +19,9 @@ log = logging.getLogger(__name__)
 class ValidationCoordinator:
     """Coordinates validation across plugin models and core options."""
 
-    def __init__(self, plugin_manager: pluggy.PluginManager):
+    def __init__(self, plugin_manager: OcrmypdfPluginManager):
         self.plugin_manager = plugin_manager
-        self.registry = getattr(plugin_manager, '_option_registry', None)
+        self.registry = plugin_manager._option_registry
 
     def validate_all_options(self, options: OcrOptions) -> None:
         """Run comprehensive validation on all options.
@@ -110,13 +109,18 @@ class ValidationCoordinator:
             )
 
         # Validate output type compatibility
-        if options.output_type == 'none' and str(options.output_file) not in (
+        output_file_display = (
+            os.fsdecode(options.output_file)
+            if isinstance(options.output_file, bytes)
+            else str(options.output_file)
+        )
+        if options.output_type == 'none' and output_file_display not in (
             os.devnull,
             '-',
         ):
             raise ValueError(
                 "Since you specified `--output-type none`, the output file "
-                f"{options.output_file} cannot be produced. Set the output file to "
+                f"{output_file_display} cannot be produced. Set the output file to "
                 "`-` to suppress this message."
             )
 
diff --git a/src/ocrmypdf/api.py b/src/ocrmypdf/api.py
index 9a0073b7..92b5f7fe 100644
--- a/src/ocrmypdf/api.py
+++ b/src/ocrmypdf/api.py
@@ -50,6 +50,8 @@ from pathlib import Path
 from typing import BinaryIO, overload
 from warnings import warn
 
+from pydantic import BaseModel
+
 from ocrmypdf._logging import PageNumberFilter
 from ocrmypdf._options import OcrOptions
 from ocrmypdf._pipelines.hocr_to_ocr_pdf import run_hocr_to_ocr_pdf_pipeline
@@ -106,7 +108,7 @@ def setup_plugin_infrastructure(
         plugin_manager = get_plugin_manager(plugins)
 
     # Initialize plugins (pass the underlying pluggy manager)
-    plugin_manager.initialize(plugin_manager=plugin_manager.pluggy)
+    plugin_manager.initialize(plugin_manager=plugin_manager.pluggy_manager)
 
     # Initialize plugin option registry
     from ocrmypdf._plugin_registry import PluginOptionRegistry
@@ -115,7 +117,7 @@ def setup_plugin_infrastructure(
 
     # Let plugins register their option models
     option_models = plugin_manager.register_options()
-    all_plugin_models: dict[str, type] = {}
+    all_plugin_models: dict[str, type[BaseModel]] = {}
     for plugin_options in option_models:
         if plugin_options:  # Skip None returns
             for namespace, model_class in plugin_options.items():
diff --git a/src/ocrmypdf/builtin_plugins/pypdfium.py b/src/ocrmypdf/builtin_plugins/pypdfium.py
index 58764a6d..dff51360 100644
--- a/src/ocrmypdf/builtin_plugins/pypdfium.py
+++ b/src/ocrmypdf/builtin_plugins/pypdfium.py
@@ -198,6 +198,7 @@ def _process_image_for_output(
         'png16m',
         'pngalpha',
     )
+    format_name: Literal['PNG', 'TIFF', 'JPEG']
     if raster_device_lower in png_devices:
         format_name = 'PNG'
     elif raster_device_lower in ('jpeg', 'jpeggray', 'jpg'):
diff --git a/src/ocrmypdf/builtin_plugins/tesseract_ocr.py b/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
index 42be9cf7..11b81b39 100644
--- a/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
+++ b/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
@@ -168,7 +168,7 @@ class TesseractOptions(BaseModel):
         tess.add_argument(
             f'--{namespace}-timeout',
             default=180.0,
-            type=numeric(float, 0),
+            type=numeric(float, 0.0),
             metavar='SECONDS',
             dest=f'{namespace}_timeout',
             help=(
@@ -183,7 +183,7 @@ class TesseractOptions(BaseModel):
         tess.add_argument(
             f'--{namespace}-non-ocr-timeout',
             default=180.0,
-            type=numeric(float, 0),
+            type=numeric(float, 0.0),
             metavar='SECONDS',
             dest=f'{namespace}_non_ocr_timeout',
             help=(
diff --git a/src/ocrmypdf/cli.py b/src/ocrmypdf/cli.py
index 1cff9db6..df754b9d 100644
--- a/src/ocrmypdf/cli.py
+++ b/src/ocrmypdf/cli.py
@@ -362,7 +362,7 @@ Online documentation is located at:
     )
     ocrsettings.add_argument(
         '--skip-big',
-        type=numeric(float, 0, 5000),
+        type=numeric(float, 0.0, 5000.0),
         metavar='MPixels',
         help="Skip OCR on pages larger than the specified amount of megapixels, "
         "but include skipped pages in final output",
@@ -398,7 +398,7 @@ Online documentation is located at:
     advanced.add_argument(
         '--max-image-mpixels',
         action='store',
-        type=numeric(float, 0),
+        type=numeric(float, 0.0),
         metavar='MPixels',
         help="Set maximum number of megapixels to unpack before treating an image as a "
         "decompression bomb",
@@ -438,14 +438,14 @@ Online documentation is located at:
     advanced.add_argument(
         '--rotate-pages-threshold',
         default=DEFAULT_ROTATE_PAGES_THRESHOLD,
-        type=numeric(float, 0, 1000),
+        type=numeric(float, 0.0, 1000.0),
         metavar='CONFIDENCE',
         help="Only rotate pages when confidence is above this value (arbitrary "
         "units reported by tesseract)",
     )
     advanced.add_argument(
         '--fast-web-view',
-        type=numeric(float, 0),
+        type=numeric(float, 0.0),
         default=1.0,
         metavar="MEGABYTES",
         help="If the size of file is more than this threshold (in MB), then "
diff --git a/src/ocrmypdf/helpers.py b/src/ocrmypdf/helpers.py
index 9884e245..94cdc657 100644
--- a/src/ocrmypdf/helpers.py
+++ b/src/ocrmypdf/helpers.py
@@ -18,6 +18,7 @@ from math import isclose, isfinite
 from pathlib import Path
 from statistics import harmonic_mean
 from typing import (
+    TYPE_CHECKING,
     Any,
     Generic,
     TypeVar,
@@ -26,6 +27,9 @@ from typing import (
 import img2pdf
 import pikepdf
 
+if TYPE_CHECKING:
+    from _typeshed import StrOrBytesPath
+
 log = logging.getLogger(__name__)
 
 IMG2PDF_KWARGS = dict(engine=img2pdf.Engine.pikepdf, rotation=img2pdf.Rotation.ifvalid)
@@ -135,7 +139,7 @@ class Resolution(Generic[T]):
         return self._isclose(self.x, other.x) and self._isclose(self.y, other.y)
 
 
-def safe_symlink(input_file: os.PathLike, soft_link_name: os.PathLike) -> None:
+def safe_symlink(input_file: StrOrBytesPath, soft_link_name: StrOrBytesPath) -> None:
     """Create a symbolic link at ``soft_link_name``, which references ``input_file``.
 
     Think of this as copying ``input_file`` to ``soft_link_name`` with less overhead.
@@ -159,11 +163,15 @@ def safe_symlink(input_file: os.PathLike, soft_link_name: os.PathLike) -> None:
     if os.path.lexists(soft_link_name):
         # do not delete or overwrite real (non-soft link) file
         if not os.path.islink(soft_link_name):
-            raise FileExistsError(f"{soft_link_name} exists and is not a link")
+            raise FileExistsError(
+                f"{os.fsdecode(soft_link_name)} exists and is not a link"
+            )
         os.unlink(soft_link_name)
 
     if not os.path.exists(input_file):
-        raise FileNotFoundError(f"trying to create a broken symlink to {input_file}")
+        raise FileNotFoundError(
+            f"trying to create a broken symlink to {os.fsdecode(input_file)}"
+        )
 
     if os.name == 'nt':
         # Don't actually use symlinks on Windows due to permission issues
@@ -214,7 +222,7 @@ def available_cpu_count() -> int:
     return 1
 
 
-def is_file_writable(test_file: os.PathLike) -> bool:
+def is_file_writable(test_file: StrOrBytesPath) -> bool:
     """Intentionally racy test if target is writable.
 
     We intend to write to the output file if and only if we succeed and
@@ -222,7 +230,7 @@ def is_file_writable(test_file: os.PathLike) -> bool:
     the location is writable.
     """
     try:
-        p = Path(test_file)
+        p = Path(os.fsdecode(test_file))
         if p.is_symlink():
             p = p.resolve(strict=False)
 
diff --git a/src/ocrmypdf/pdfinfo/_worker.py b/src/ocrmypdf/pdfinfo/_worker.py
index f0da8926..01c4b458 100644
--- a/src/ocrmypdf/pdfinfo/_worker.py
+++ b/src/ocrmypdf/pdfinfo/_worker.py
@@ -28,7 +28,7 @@ logger = logging.getLogger()
 worker_pdf = None  # pylint: disable=invalid-name
 
 
-def _pdf_pageinfo_sync_init(pdf: Pdf, infile: Path, pdfminer_loglevel):
+def _pdf_pageinfo_sync_init(pdf: Pdf | None, infile: Path, pdfminer_loglevel):
     global worker_pdf  # pylint: disable=global-statement,invalid-name
     pikepdf_enable_mmap()
 
@@ -75,13 +75,13 @@ def _pdf_pageinfo_sync(
 
 
 def _pdf_pageinfo_concurrent(
-    pdf,
+    pdf: Pdf,
     executor: Executor,
-    max_workers: int,
+    max_workers: int | None,
     use_threads: bool,
-    infile,
-    progbar,
-    check_pages,
+    infile: Path,
+    progbar: bool,
+    check_pages: Container[int],
     detailed_analysis: bool = False,
     miner_state: PdfMinerState | None = None,
 ) -> Sequence[PageInfo | None]:
diff --git a/src/ocrmypdf/pdfinfo/layout.py b/src/ocrmypdf/pdfinfo/layout.py
index a7290c60..15ad1bfd 100644
--- a/src/ocrmypdf/pdfinfo/layout.py
+++ b/src/ocrmypdf/pdfinfo/layout.py
@@ -5,19 +5,19 @@
 from __future__ import annotations
 
 import re
+import sys
 from collections.abc import Iterator, Mapping
 from contextlib import contextmanager
 from math import copysign
 from os import PathLike
 from pathlib import Path
-from typing import Any
+from typing import Any, BinaryIO
 from unittest.mock import patch
 
 import pdfminer
 import pdfminer.encodingdb
 import pdfminer.pdfdevice
 import pdfminer.pdfinterp
-from deprecation import deprecated
 from pdfminer.converter import PDFLayoutAnalyzer
 from pdfminer.layout import LAParams, LTChar, LTPage, LTTextBox
 from pdfminer.pdfcolor import PDFColorSpace
@@ -30,6 +30,11 @@ from pdfminer.utils import Matrix, bbox2str, matrix2str
 
 from ocrmypdf.exceptions import EncryptedPdfError, InputFileError
 
+if sys.version_info >= (3, 13):
+    from warnings import deprecated
+else:
+    from typing_extensions import deprecated
+
 STRIP_NAME = re.compile(r'[0-9]+')
 
 
@@ -57,7 +62,7 @@ def pdfsimplefont__init__(
     return
 
 
-PDFSimpleFont.__init__ = pdfsimplefont__init__
+PDFSimpleFont.__init__ = pdfsimplefont__init__  # type: ignore[method-assign]
 
 
 def pdftype3font__pscript5_get_height(self):
@@ -284,7 +289,7 @@ def patch_pdfminer(pscript5_mode: bool):
         yield
 
 
-@deprecated(deprecated_in='16.6.0', details='Use PdfMinerState instead.')
+@deprecated('Deprecated since 16.6.0; use PdfMinerState instead.')
 def get_page_analysis(
     infile: PathLike, pageno: int, pscript5_mode: bool
 ) -> LTPage | None:
@@ -332,10 +337,10 @@ class PdfMinerState:
         self.infile = infile
         self.rman = pdfminer.pdfinterp.PDFResourceManager(caching=True)
         self.disable_boxes_flow = None
-        self.page_iter = None
+        self.page_iter: Iterator[PDFPage] | None = None
         self.page_cache: list[PDFPage] = []
         self.pscript5_mode = pscript5_mode
-        self.file = None
+        self.file: BinaryIO | None = None
 
     def __enter__(self):
         """Enter the context manager."""
@@ -351,6 +356,7 @@ class PdfMinerState:
 
     def get_page_analysis(self, pageno: int):
         """Get the page analysis for a given page."""
+        assert self.page_iter is not None, "must be used as a context manager"
         while len(self.page_cache) <= pageno:
             try:
                 self.page_cache.append(next(self.page_iter))
diff --git a/uv.lock b/uv.lock
index 5fce9aad..48fc5556 100644
--- a/uv.lock
+++ b/uv.lock
@@ -576,18 +576,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/07/6c/aa3f2f849e01cb6a001cd8554a88d4c77c5c1a31c95bdf1cf9301e6d9ef4/defusedxml-0.7.1-py2.py3-none-any.whl", hash = "sha256:a352e7e428770286cc899e2542b6cdaedb2b4953ff269a210103ec58f6198a61", size = 25604, upload-time = "2021-03-08T10:59:24.45Z" },
 ]
 
-[[package]]
-name = "deprecation"
-version = "2.1.0"
-source = { registry = "https://pypi.org/simple" }
-dependencies = [
-    { name = "packaging" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/5a/d3/8ae2869247df154b64c1884d7346d412fed0c49df84db635aab2d1c40e62/deprecation-2.1.0.tar.gz", hash = "sha256:72b3bde64e5d778694b0cf68178aed03d15e15477116add3fb773e581f9518ff", size = 173788, upload-time = "2020-04-20T14:23:38.738Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/02/c3/253a89ee03fc9b9682f1541728eb66db7db22148cd94f89ab22528cd1e1b/deprecation-2.1.0-py2.py3-none-any.whl", hash = "sha256:a10811591210e1fb0e768a8c25517cabeabcba6f0bf96564f8ff45189f90b14a", size = 11178, upload-time = "2020-04-20T14:23:36.581Z" },
-]
-
 [[package]]
 name = "docstring-parser"
 version = "0.18.0"
@@ -1437,7 +1425,6 @@ name = "ocrmypdf"
 version = "17.8.0"
 source = { editable = "." }
 dependencies = [
-    { name = "deprecation" },
     { name = "fpdf2" },
     { name = "img2pdf" },
     { name = "packaging" },
@@ -1449,6 +1436,7 @@ dependencies = [
     { name = "pydantic" },
     { name = "pypdfium2" },
     { name = "rich" },
+    { name = "typing-extensions", marker = "python_full_version < '3.13'" },
     { name = "uharfbuzz" },
 ]
 
@@ -1501,7 +1489,6 @@ test = [
 [package.metadata]
 requires-dist = [
     { name = "cyclopts", marker = "extra == 'watcher'", specifier = ">=3" },
-    { name = "deprecation", specifier = ">=2.1.0" },
     { name = "fpdf2", specifier = ">=2.8.0" },
     { name = "img2pdf", specifier = ">=0.5" },
     { name = "packaging", specifier = ">=20" },
@@ -1515,6 +1502,7 @@ requires-dist = [
     { name = "python-dotenv", marker = "extra == 'watcher'" },
     { name = "rich", specifier = ">=13" },
     { name = "streamlit", marker = "extra == 'webservice'", specifier = ">=1.41.0" },
+    { name = "typing-extensions", marker = "python_full_version < '3.13'", specifier = ">=4.12" },
     { name = "uharfbuzz", specifier = ">=0.53.2" },
     { name = "watchdog", marker = "extra == 'watcher'", specifier = ">=1.0.2" },
 ]