diff --git a/docs/conf.py b/docs/conf.py
index 96927133..a4a8f636 100755
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -25,10 +25,11 @@
 # sys.path.insert(0, os.path.abspath('.'))
 
 # -- General configuration ------------------------------------------------
+from __future__ import annotations
 
 needs_sphinx = '8'
 
-import datetime
+import datetime as dt
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -63,7 +64,7 @@ master_doc = 'index'
 # General information about the project.
 project = 'ocrmypdf'
 
-year = str(datetime.date.today().year)
+year = str(dt.date.today().year)
 copyright = (
     f'{year}, James R. Barlow. '
     + 'Licensed under Creative Commons Attribution-ShareAlike 4.0'
diff --git a/misc/_webservice.py b/misc/_webservice.py
index 6016080e..df7752f0 100644
--- a/misc/_webservice.py
+++ b/misc/_webservice.py
@@ -96,7 +96,9 @@ with st.expander("Optimization after OCR"):
     png_quality = st.slider(
         "PNG quality", min_value=0, max_value=100, value=75, key="png_quality"
     )
-    jbig2_threshold = st.number_input("JBIG2 threshold", value=0.85, key="jbig2_threshold")
+    jbig2_threshold = st.number_input(
+        "JBIG2 threshold", value=0.85, key="jbig2_threshold"
+    )
 
 with st.expander("Advanced options"):
     jobs = st.slider(
@@ -192,45 +194,47 @@ if uploaded:
         args.append(f"--jbig2-threshold={jbig2_threshold}")
     if jobs:
         args.append(f"--jobs={jobs}")
-    input_file = NamedTemporaryFile(delete=True, suffix=f"_{uploaded.name}")
-    input_file.write(uploaded.getvalue())
-    input_file.flush()
-    input_file.seek(0)
-    args.append(str(input_file.name))
-    output_file = NamedTemporaryFile(delete=True, suffix=".pdf")
-    args.append(str(output_file.name))
+    with NamedTemporaryFile(delete=True, suffix=f"_{uploaded.name}") as input_file:
+        input_file.write(uploaded.getvalue())
+        input_file.flush()
+        input_file.seek(0)
+        args.append(str(input_file.name))
+        with NamedTemporaryFile(delete=True, suffix=".pdf") as output_file:
+            args.append(str(output_file.name))
 
-    st.session_state['running'] = (
-        'run_button' in st.session_state and st.session_state.run_button
-    )
-    if st.button(
-        "Run OCRmyPDF",
-        disabled=st.session_state.get("running", False),
-        key='run_button',
-    ):
-        st.session_state['running'] = True
-        args = [sys.executable, '-u', '-m', "ocrmypdf"] + args
+            st.session_state['running'] = (
+                'run_button' in st.session_state and st.session_state.run_button
+            )
+            if st.button(
+                "Run OCRmyPDF",
+                disabled=st.session_state.get("running", False),
+                key='run_button',
+            ):
+                st.session_state['running'] = True
+                args = [sys.executable, '-u', '-m', "ocrmypdf"] + args
 
-        proc = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        with st.container(border=True):
-            while proc.poll() is None:
-                line = proc.stderr.readline()
-                if line:
-                    st.html("<code>" + line.decode().strip() + "</code>")
+                proc = subprocess.Popen(
+                    args, stdout=subprocess.PIPE, stderr=subprocess.PIPE
+                )
+                with st.container(border=True):
+                    while proc.poll() is None:
+                        line = proc.stderr.readline()
+                        if line:
+                            st.html("<code>" + line.decode().strip() + "</code>")
 
-        if proc.returncode != 0:
-            st.error(f"ocrmypdf failed with exit code {proc.returncode}")
-            st.session_state['running'] = False
-            st.stop()
+                if proc.returncode != 0:
+                    st.error(f"ocrmypdf failed with exit code {proc.returncode}")
+                    st.session_state['running'] = False
+                    st.stop()
 
-        if Path(output_file.name).stat().st_size == 0:
-            st.error("No output PDF file was generated")
-            st.stop()
+                if Path(output_file.name).stat().st_size == 0:
+                    st.error("No output PDF file was generated")
+                    st.stop()
 
-        st.download_button(
-            label="Download output PDF",
-            data=output_file.read(),
-            file_name=uploaded.name,
-            mime="application/pdf",
-        )
-        st.session_state['running'] = False
+                st.download_button(
+                    label="Download output PDF",
+                    data=output_file.read(),
+                    file_name=uploaded.name,
+                    mime="application/pdf",
+                )
+                st.session_state['running'] = False
diff --git a/misc/batch.py b/misc/batch.py
index a9e45ac2..f45e8919 100644
--- a/misc/batch.py
+++ b/misc/batch.py
@@ -39,10 +39,7 @@ script_dir = Path(__file__).parent
 # set archive_dir to a path for backup original documents. Leave empty if not required.
 archive_dir = "/pdfbak"
 
-if len(sys.argv) > 1:
-    start_dir = Path(sys.argv[1])
-else:
-    start_dir = Path(".")
+start_dir = Path(sys.argv[1]) if len(sys.argv) > 1 else Path(".")
 
 if len(sys.argv) > 2:
     log_file = Path(sys.argv[2])
diff --git a/misc/bisect_pdf.py b/misc/bisect_pdf.py
index 79cd8f98..b50aec07 100644
--- a/misc/bisect_pdf.py
+++ b/misc/bisect_pdf.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: MIT
 
 """Helper script for bisecting PDFs to find a page with an issue."""
+from __future__ import annotations
 
 import sys
 
diff --git a/misc/watcher.py b/misc/watcher.py
index 95447905..7d1f421f 100644
--- a/misc/watcher.py
+++ b/misc/watcher.py
@@ -7,12 +7,12 @@
 
 from __future__ import annotations
 
+import datetime as dt
 import json
 import logging
 import shutil
 import sys
 import time
-from datetime import datetime
 from enum import Enum
 from pathlib import Path
 from typing import Annotated, Any
@@ -48,7 +48,7 @@ class LoggingLevelEnum(str, Enum):
 def get_output_path(root: Path, basename: str, output_dir_year_month: bool) -> Path:
     assert '/' not in basename, "basename must not contain '/'"
     if output_dir_year_month:
-        today = datetime.today()
+        today = dt.datetime.today()
         output_directory_year_month = root / str(today.year) / f'{today.month:02d}'
         if not output_directory_year_month.exists():
             output_directory_year_month.mkdir(parents=True, exist_ok=True)
@@ -140,7 +140,7 @@ class HandleObserverEvent(PatternMatchingEventHandler):
         ignore_patterns=None,
         ignore_directories=False,
         case_sensitive=False,
-        settings={},
+        settings=None,
     ):
         super().__init__(
             patterns=patterns,
@@ -148,7 +148,7 @@ class HandleObserverEvent(PatternMatchingEventHandler):
             ignore_directories=ignore_directories,
             case_sensitive=case_sensitive,
         )
-        self._settings = settings
+        self._settings = settings if settings else {}
 
     def on_any_event(self, event):
         if event.event_type in ['created']:
@@ -302,10 +302,7 @@ def main(
             'output_dir_year_month': output_dir_year_month,
         },
     )
-    if use_polling:
-        observer = PollingObserver()
-    else:
-        observer = Observer()
+    observer = PollingObserver() if use_polling else Observer()
     observer.schedule(handler, input_dir, recursive=True)
     observer.start()
     print(f"Watching {input_dir} for new PDFs. Press Ctrl+C to exit.")
diff --git a/misc/webservice.py b/misc/webservice.py
index a432f50e..d3584414 100755
--- a/misc/webservice.py
+++ b/misc/webservice.py
@@ -4,6 +4,8 @@
 
 """Run the OCRmyPDF web service."""
 
+from __future__ import annotations
+
 import os
 import sys
 
@@ -13,7 +15,7 @@ except ImportError:
     raise ImportError(
         'You need to install streamlit in the Python environment '
         'to run the web service.\n'
-    )
+    ) from None
 
 if __name__ == '__main__':
     os.execvp(
diff --git a/pyproject.toml b/pyproject.toml
index 06da8f66..01d95e9b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -130,6 +130,7 @@ exclude = ["src/ocrmypdf/_version.py"] # Autogenerated
   "UP",  # pyupgrade
   "SIM", # simplify
   "B",   # flake8-bugbear
+  "ICN", # flake8-import-conventions
 ]
 ignore = [
   "B028", # warning with no explicit stacklevel
@@ -139,13 +140,20 @@ ignore = [
 
 [tool.ruff.lint.isort]
 known-first-party = ["ocrmypdf"]
+required-imports = ["from __future__ import annotations"]
+
+[tool.ruff.lint.flake8-import-conventions]
+# Prohibit explicit imports from the 'datetime' module
+banned-from = ["datetime"]
+# Optionally, suggest an alias for 'import datetime' (e.g., as dt)
+extend-aliases = { "datetime" = "dt" }
 
 [tool.ruff.lint.pydocstyle]
 convention = "google"
 
 [tool.ruff.lint.per-file-ignores]
 "docs/conf.py" = ["D100", "D101", "D105"]
-"tests/*.py" = ["D100", "D101", "D102", "D103", "D105"]
+"tests/*.py" = ["D100", "D101", "D102", "D103", "D105", "E501"]
 "misc/*.py" = ["D103", "D101", "D102"]
 "src/ocrmypdf/builtin_plugins/*.py" = ["D103", "D102", "D105"]
 
@@ -154,11 +162,7 @@ quote-style = "preserve"
 
 [dependency-groups]
 # Developer-only tools - use `uv sync --group <name>`
-dev = [
-    "mypy>=1.13.0",
-    "ipykernel>=6.29.5",
-    "reportlab>=4.4.4",
-]
+dev = ["mypy>=1.13.0", "ipykernel>=6.29.5", "reportlab>=4.4.4"]
 test = [
   # Core testing framework
   "coverage[toml]>=6.2",
@@ -175,5 +179,11 @@ test = [
   # Extended test capabilities (merged from extended_test)
   "pymupdf>=1.24.14",
 ]
-docs = ["myst-parser>=4.0.1", "sphinx", "sphinx-issues", "sphinx-rtd-theme", "sphinxcontrib-mermaid"]
+docs = [
+  "myst-parser>=4.0.1",
+  "sphinx",
+  "sphinx-issues",
+  "sphinx-rtd-theme",
+  "sphinxcontrib-mermaid",
+]
 streamlit-dev = ["streamlit>=1.40.2", "streamlit-pdf-viewer>=0.0.19"]
diff --git a/src/ocrmypdf/_defaults.py b/src/ocrmypdf/_defaults.py
index 39674286..c979b8eb 100644
--- a/src/ocrmypdf/_defaults.py
+++ b/src/ocrmypdf/_defaults.py
@@ -2,6 +2,8 @@
 # SPDX-License-Identifier: MPL-2.0
 
 # Enforce English hegemony
+from __future__ import annotations
+
 DEFAULT_LANGUAGE = 'eng'
 
 # Default rotation threshold
diff --git a/src/ocrmypdf/_exec/ghostscript.py b/src/ocrmypdf/_exec/ghostscript.py
index 92f757fe..b48f2080 100644
--- a/src/ocrmypdf/_exec/ghostscript.py
+++ b/src/ocrmypdf/_exec/ghostscript.py
@@ -111,6 +111,15 @@ def rasterize_pdf(
     """Rasterize one page of a PDF at resolution raster_dpi in canvas units.
 
     Args:
+        input_file: The PDF file to rasterize.
+        output_file: The file to write the rasterized PDF to.
+        raster_device: The Ghostscript raster device to use to rasterize the PDF.
+        raster_dpi: Resolution in dots per inch at which to rasterize page.
+        pageno: Page number to rasterize (beginning at page 1).
+        page_dpi: Resolution, overriding output image DPI.
+        rotation: Cardinal angle, clockwise, to rotate page.
+        filter_vector: If True, remove vector graphics objects.
+        stop_on_error: If True, stop rasterizing on the first error.
         use_cropbox: If True, rasterize the CropBox instead of MediaBox.
             Default is False (use MediaBox).
     """
diff --git a/src/ocrmypdf/_metadata.py b/src/ocrmypdf/_metadata.py
index 74c13022..f973a2a0 100644
--- a/src/ocrmypdf/_metadata.py
+++ b/src/ocrmypdf/_metadata.py
@@ -5,9 +5,9 @@
 
 from __future__ import annotations
 
+import datetime as dt
 import logging
 import os
-from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any
 
@@ -53,7 +53,7 @@ def get_docinfo(base_pdf: Pdf, context: PdfContext) -> dict[str, str]:
 
     pdfmark['/Creator'] = f'{PROGRAM_NAME} {OCRMYPF_VERSION} / {creator_tag}'
     pdfmark['/Producer'] = f'pikepdf {PIKEPDF_VERSION}'
-    pdfmark['/ModDate'] = encode_pdf_date(datetime.now(timezone.utc))
+    pdfmark['/ModDate'] = encode_pdf_date(dt.datetime.now(dt.UTC))
     return pdfmark
 
 
diff --git a/src/ocrmypdf/_pipelines/ocr.py b/src/ocrmypdf/_pipelines/ocr.py
index d875be0e..dd0288e7 100644
--- a/src/ocrmypdf/_pipelines/ocr.py
+++ b/src/ocrmypdf/_pipelines/ocr.py
@@ -50,7 +50,7 @@ from ocrmypdf._validation import (
 )
 from ocrmypdf.exceptions import ExitCode
 from ocrmypdf.helpers import available_cpu_count
-from ocrmypdf.hocrtransform.ocr_element import OcrElement
+from ocrmypdf.models.ocr_element import OcrElement
 
 log = logging.getLogger(__name__)
 
diff --git a/src/ocrmypdf/font/__init__.py b/src/ocrmypdf/font/__init__.py
index 306808d7..f94cc3cb 100644
--- a/src/ocrmypdf/font/__init__.py
+++ b/src/ocrmypdf/font/__init__.py
@@ -10,6 +10,7 @@ This module provides font infrastructure for the fpdf2 PDF renderer. It includes
 - MultiFontManager: Automatic font selection for multilingual documents
 - SystemFontProvider: System font discovery
 """
+from __future__ import annotations
 
 from ocrmypdf.font.font_manager import FontManager
 from ocrmypdf.font.font_provider import (
diff --git a/src/ocrmypdf/fpdf_renderer/__init__.py b/src/ocrmypdf/fpdf_renderer/__init__.py
index 82466b3c..db039f9e 100644
--- a/src/ocrmypdf/fpdf_renderer/__init__.py
+++ b/src/ocrmypdf/fpdf_renderer/__init__.py
@@ -6,6 +6,7 @@
 This module provides the PDF renderer using fpdf2 for creating
 searchable OCR text layers.
 """
+from __future__ import annotations
 
 from ocrmypdf.fpdf_renderer.renderer import (
     DebugRenderOptions,
diff --git a/src/ocrmypdf/helpers.py b/src/ocrmypdf/helpers.py
index 7b810de2..9884e245 100644
--- a/src/ocrmypdf/helpers.py
+++ b/src/ocrmypdf/helpers.py
@@ -25,7 +25,6 @@ from typing import (
 
 import img2pdf
 import pikepdf
-from deprecation import deprecated
 
 log = logging.getLogger(__name__)
 
diff --git a/src/ocrmypdf/hocrtransform/__main__.py b/src/ocrmypdf/hocrtransform/__main__.py
index df561174..76375293 100644
--- a/src/ocrmypdf/hocrtransform/__main__.py
+++ b/src/ocrmypdf/hocrtransform/__main__.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 """Simple CLI for testing HOCR to PDF conversion using fpdf2 renderer."""
+from __future__ import annotations
 
 import argparse
 from pathlib import Path
diff --git a/src/ocrmypdf/languages.py b/src/ocrmypdf/languages.py
index 90e36775..0702fe53 100644
--- a/src/ocrmypdf/languages.py
+++ b/src/ocrmypdf/languages.py
@@ -6,6 +6,7 @@
 Derived from
 https://www.loc.gov/standards/iso639-2/ascii_8bits.html
 """
+from __future__ import annotations
 
 from typing import NamedTuple
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 05088071..472aaee0 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -23,9 +23,10 @@ class Gs106WarningFilter(logging.Filter):
 
     def filter(self, record: logging.LogRecord) -> bool:
         # Allow all records except the expected Ghostscript 10.6.x warning
-        if "Ghostscript 10.6.x contains JPEG encoding errors" in record.getMessage():
-            return False
-        return True
+        return (
+            "Ghostscript 10.6.x contains JPEG encoding errors"
+            not in record.getMessage()
+        )
 
 
 @pytest.fixture(autouse=True)
diff --git a/tests/test_json_serialization.py b/tests/test_json_serialization.py
index 3de76ed5..e08a8bfe 100644
--- a/tests/test_json_serialization.py
+++ b/tests/test_json_serialization.py
@@ -1,4 +1,5 @@
 """Test JSON serialization of OcrOptions for multiprocessing compatibility."""
+from __future__ import annotations
 
 import multiprocessing
 from io import BytesIO
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index 80da5f6b..be8826bb 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -3,9 +3,8 @@
 
 from __future__ import annotations
 
-import datetime
+import datetime as dt
 import warnings
-from datetime import timezone
 from shutil import copyfile
 
 import pikepdf
@@ -198,10 +197,7 @@ def test_creation_date_preserved(output_type, resources, infile, outpdf):
 
         # We expect that the modified date is quite recent
         date_after = decode_pdf_date(str(after['/ModDate']))
-        assert (
-            seconds_between_dates(date_after, datetime.datetime.now(timezone.utc))
-            < 1000
-        )
+        assert seconds_between_dates(date_after, dt.datetime.now(dt.UTC)) < 1000
 
 
 @pytest.fixture
diff --git a/tests/test_multilingual_direct.py b/tests/test_multilingual_direct.py
index 0a5fe35d..113e29d2 100644
--- a/tests/test_multilingual_direct.py
+++ b/tests/test_multilingual_direct.py
@@ -10,6 +10,7 @@ This tests the fpdf2 renderer with various language groups:
 - CJK (Chinese Simplified/Traditional, Japanese, Korean)
 - Devanagari (Hindi, Sanskrit)
 """
+from __future__ import annotations
 
 import shutil
 import subprocess
diff --git a/tests/test_unpaper.py b/tests/test_unpaper.py
index 31425cba..319748da 100644
--- a/tests/test_unpaper.py
+++ b/tests/test_unpaper.py
@@ -119,7 +119,7 @@ def test_unpaper_args_invalid(resources, outpdf):
 def test_unpaper_image_too_big(resources, outdir, caplog):
     with patch('ocrmypdf._exec.unpaper.UNPAPER_IMAGE_PIXEL_LIMIT', 42):
         infile = resources / 'crom.png'
-        unpaper.clean(infile, outdir / 'out.png', dpi=300) == infile
+        assert unpaper.clean(infile, outdir / 'out.png', dpi=300) == infile
 
         assert any(
             'too large for cleaning' in rec.message
diff --git a/tests/test_watcher.py b/tests/test_watcher.py
index 40b01089..8cfcaf7e 100644
--- a/tests/test_watcher.py
+++ b/tests/test_watcher.py
@@ -1,4 +1,6 @@
-import datetime
+from __future__ import annotations
+
+import datetime as dt
 import os
 import shutil
 import subprocess
@@ -43,8 +45,8 @@ def test_watcher(tmp_path, resources, year_month):
     if year_month:
         assert (
             output_dir
-            / f'{datetime.date.today().year}'
-            / f'{datetime.date.today().month:02d}'
+            / f'{dt.date.today().year}'
+            / f'{dt.date.today().month:02d}'
             / 'trivial.pdf'
         ).exists()
     else: