diff --git a/src/ocrmypdf/_pipeline.py b/src/ocrmypdf/_pipeline.py
index 0806880e..6e67d808 100644
--- a/src/ocrmypdf/_pipeline.py
+++ b/src/ocrmypdf/_pipeline.py
@@ -321,9 +321,9 @@ def rasterize_preview(input_file, page_context):
     output_file = page_context.get_path('rasterize_preview.jpg')
     canvas_dpi = get_canvas_square_dpi(page_context.pageinfo, page_context.options)
     page_dpi = get_page_square_dpi(page_context.pageinfo, page_context.options)
-    ghostscript.rasterize_pdf(
-        input_file,
-        output_file,
+    page_context.plugin_manager.hook.rasterize_pdf_page(
+        input_file=input_file,
+        output_file=output_file,
         raster_device='jpeggray',
         raster_dpi=canvas_dpi,
         page_dpi=page_dpi,
@@ -430,9 +430,9 @@ def rasterize(
     canvas_dpi = get_canvas_square_dpi(pageinfo, page_context.options)
     page_dpi = get_page_square_dpi(pageinfo, page_context.options)
 
-    ghostscript.rasterize_pdf(
-        input_file,
-        output_file,
+    page_context.plugin_manager.hook.rasterize_pdf_page(
+        input_file=input_file,
+        output_file=output_file,
         raster_device=device,
         raster_dpi=canvas_dpi,
         page_dpi=page_dpi,
diff --git a/src/ocrmypdf/_plugin_manager.py b/src/ocrmypdf/_plugin_manager.py
index 1fbc1b76..9f328c69 100644
--- a/src/ocrmypdf/_plugin_manager.py
+++ b/src/ocrmypdf/_plugin_manager.py
@@ -33,7 +33,10 @@ def get_plugin_manager(plugins: List[str], builtins=True):
     pm.add_hookspecs(pluginspec)
 
     if builtins:
-        all_plugins = ['ocrmypdf.builtin_plugins'] + plugins
+        all_plugins = [
+            'ocrmypdf.builtin_plugins.ghostscript',
+            'ocrmypdf.builtin_plugins.tesseract_ocr',
+        ] + plugins
     else:
         all_plugins = plugins
     for name in all_plugins:
diff --git a/src/ocrmypdf/_validation.py b/src/ocrmypdf/_validation.py
index 941e3522..3a92d34c 100644
--- a/src/ocrmypdf/_validation.py
+++ b/src/ocrmypdf/_validation.py
@@ -27,7 +27,6 @@ from shutil import copyfileobj
 
 import PIL
 
-from ocrmypdf._plugin_manager import get_plugin_manager
 from ocrmypdf._unicodefun import verify_python3_env
 from ocrmypdf.exceptions import (
     BadArgsError,
@@ -35,14 +34,7 @@ from ocrmypdf.exceptions import (
     MissingDependencyError,
     OutputFileAccessError,
 )
-from ocrmypdf.exec import (
-    check_external_program,
-    ghostscript,
-    jbig2enc,
-    pngquant,
-    tesseract,
-    unpaper,
-)
+from ocrmypdf.exec import check_external_program, jbig2enc, pngquant, unpaper
 from ocrmypdf.helpers import (
     is_file_writable,
     is_iterable_notstr,
@@ -92,10 +84,6 @@ def check_options_languages(options, plugin_manager):
 
 
 def check_options_output(options):
-    # We have these constraints to check for.
-    # 1. Ghostscript < 9.20 mangles multibyte Unicode
-    # 2. hocr doesn't work on non-Latin languages (so don't select it)
-
     is_latin = options.languages.issubset(HOCR_OK_LANGS)
 
     if options.pdf_renderer == 'hocr' and not is_latin:
@@ -106,25 +94,6 @@ def check_options_output(options):
         )
         log.warning(msg)
 
-    if ghostscript.version() < '9.20' and options.output_type != 'pdf' and not is_latin:
-        # https://bugs.ghostscript.com/show_bug.cgi?id=696874
-        # Ghostscript < 9.20 fails to encode multibyte characters properly
-        msg = (
-            "The installed version of Ghostscript does not work correctly "
-            "with the OCR languages you specified. Use --output-type pdf or "
-            "upgrade to Ghostscript 9.20 or later to avoid this issue."
-        )
-        msg += f"Found Ghostscript {ghostscript.version()}"
-        log.warning(msg)
-
-    if options.output_type == 'pdfa':
-        options.output_type = 'pdfa-2'
-
-    if options.output_type == 'pdfa-3' and ghostscript.version() < '9.19':
-        raise MissingDependencyError(
-            "--output-type pdfa-3 requires Ghostscript 9.19 or later"
-        )
-
     lossless_reconstruction = False
     if not any(
         (
@@ -291,7 +260,6 @@ def check_options(options, plugin_manager):
     check_options_optimizing(options)
     check_options_advanced(options)
     check_options_pillow(options)
-    check_dependency_versions(options)
     plugin_manager.hook.check_options(options=options)
 
 
@@ -432,19 +400,3 @@ def report_output_file_size(options, input_file, output_file):
         f"The output file size is {ratio:.2f}× larger than the input file.\n"
         f"{explanation}"
     )
-
-
-def check_dependency_versions(options):
-    check_external_program(
-        program='gs',
-        package='ghostscript',
-        version_checker=ghostscript.version,
-        need_version='9.15',  # limited by Travis CI / Ubuntu 14.04 backports
-    )
-    gs_version = ghostscript.version()
-    if gs_version in ('9.24', '9.51'):
-        raise MissingDependencyError(
-            f"Ghostscript {gs_version} contains serious regressions and is not "
-            "supported. Please upgrade to a newer version, or downgrade to the "
-            "previous version."
-        )
diff --git a/src/ocrmypdf/builtin_plugins/__init__.py b/src/ocrmypdf/builtin_plugins/__init__.py
index e5fd494e..0ed32bc2 100644
--- a/src/ocrmypdf/builtin_plugins/__init__.py
+++ b/src/ocrmypdf/builtin_plugins/__init__.py
@@ -14,5 +14,3 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
-
-from ocrmypdf.builtin_plugins.tesseract_ocr import *
diff --git a/src/ocrmypdf/builtin_plugins/ghostscript.py b/src/ocrmypdf/builtin_plugins/ghostscript.py
new file mode 100644
index 00000000..92f39008
--- /dev/null
+++ b/src/ocrmypdf/builtin_plugins/ghostscript.py
@@ -0,0 +1,90 @@
+# © 2020 James R. Barlow: github.com/jbarlow83
+#
+# This file is part of OCRmyPDF.
+#
+# OCRmyPDF is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# OCRmyPDF is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
+
+import logging
+from pathlib import Path
+
+from ocrmypdf import hookimpl
+from ocrmypdf._validation import HOCR_OK_LANGS
+from ocrmypdf.exceptions import MissingDependencyError
+from ocrmypdf.exec import check_external_program, ghostscript
+from ocrmypdf.helpers import Resolution
+
+log = logging.getLogger(__name__)
+
+
+@hookimpl
+def check_options(options):
+    gs_version = ghostscript.version()
+    check_external_program(
+        program='gs',
+        package='ghostscript',
+        version_checker=gs_version,
+        need_version='9.15',  # limited by Travis CI / Ubuntu 14.04 backports
+    )
+    if gs_version in ('9.24', '9.51'):
+        raise MissingDependencyError(
+            f"Ghostscript {gs_version} contains serious regressions and is not "
+            "supported. Please upgrade to a newer version, or downgrade to the "
+            "previous version."
+        )
+
+    # We have these constraints to check for.
+    # 1. Ghostscript < 9.20 mangles multibyte Unicode
+    # 2. hocr doesn't work on non-Latin languages (so don't select it)
+    is_latin = options.languages.issubset(HOCR_OK_LANGS)
+    if gs_version < '9.20' and options.output_type != 'pdf' and not is_latin:
+        # https://bugs.ghostscript.com/show_bug.cgi?id=696874
+        # Ghostscript < 9.20 fails to encode multibyte characters properly
+        msg = (
+            "The installed version of Ghostscript does not work correctly "
+            "with the OCR languages you specified. Use --output-type pdf or "
+            "upgrade to Ghostscript 9.20 or later to avoid this issue."
+        )
+        msg += f"Found Ghostscript {gs_version}"
+        log.warning(msg)
+
+    if options.output_type == 'pdfa':
+        options.output_type = 'pdfa-2'
+
+    if options.output_type == 'pdfa-3' and ghostscript.version() < '9.19':
+        raise MissingDependencyError(
+            "--output-type pdfa-3 requires Ghostscript 9.19 or later"
+        )
+
+
+@hookimpl
+def rasterize_pdf_page(
+    input_file: Path,
+    output_file: Path,
+    raster_device: str,
+    raster_dpi: Resolution,
+    pageno: int,
+    page_dpi: Resolution = None,
+    rotation: int = None,
+    filter_vector: bool = False,
+):
+    return ghostscript.rasterize_pdf(
+        input_file,
+        output_file,
+        raster_device=raster_device,
+        raster_dpi=raster_dpi,
+        pageno=pageno,
+        page_dpi=page_dpi,
+        rotation=rotation,
+        filter_vector=filter_vector,
+    )
diff --git a/src/ocrmypdf/exec/_support.py b/src/ocrmypdf/exec/_support.py
index 60d22a83..5f52ac87 100644
--- a/src/ocrmypdf/exec/_support.py
+++ b/src/ocrmypdf/exec/_support.py
@@ -280,7 +280,10 @@ def check_external_program(
     recommended=False,
 ):
     try:
-        found_version = version_checker()
+        if callable(version_checker):
+            found_version = version_checker()
+        else:
+            found_version = version_checker
     except (CalledProcessError, FileNotFoundError, MissingDependencyError):
         _error_missing_program(program, package, required_for, recommended)
         if not recommended:
diff --git a/src/ocrmypdf/exec/ghostscript.py b/src/ocrmypdf/exec/ghostscript.py
index d7407726..a43b972b 100644
--- a/src/ocrmypdf/exec/ghostscript.py
+++ b/src/ocrmypdf/exec/ghostscript.py
@@ -20,7 +20,6 @@
 import logging
 import os
 import re
-import warnings
 from io import BytesIO
 from os import fspath
 from pathlib import Path
@@ -92,22 +91,7 @@ def rasterize_pdf(
     rotation: int = None,
     filter_vector: bool = False,
 ):
-    """Rasterize one page of a PDF at resolution raster_dpi in canvas units.
-
-    The image is sized to match the integer pixels dimensions implied by
-    raster_dpi even if those numbers are noninteger. The image's DPI will
-     be overridden with the values in page_dpi.
-
-    :param input_file: pathlike
-    :param output_file: pathlike
-    :param raster_device:
-    :param raster_dpi: resolution at which to rasterize page
-    :param pageno: page number to rasterize (beginning at page 1)
-    :param page_dpi: resolution tuple (x, y) overriding output image DPI
-    :param rotation: 0, 90, 180, 270: clockwise angle to rotate page
-    :param filter_vector: if True, remove vector graphics objects
-    :return:
-    """
+    """Rasterize one page of a PDF at resolution raster_dpi in canvas units."""
     raster_dpi = raster_dpi.round(6)
     if not page_dpi:
         page_dpi = raster_dpi
diff --git a/src/ocrmypdf/pluginspec.py b/src/ocrmypdf/pluginspec.py
index dd659458..fd2498b2 100644
--- a/src/ocrmypdf/pluginspec.py
+++ b/src/ocrmypdf/pluginspec.py
@@ -24,6 +24,8 @@ from typing import AbstractSet, Optional
 import pluggy
 from PIL import Image
 
+from ocrmypdf.helpers import Resolution
+
 hookspec = pluggy.HookspecMarker('ocrmypdf')
 
 # pylint: disable=unused-argument
@@ -66,6 +68,35 @@ def validate(pdfinfo: 'PdfInfo', options: Namespace) -> None:
     """
 
 
+@hookspec(firstresult=True)
+def rasterize_pdf_page(
+    input_file: Path,
+    output_file: Path,
+    raster_device: str,
+    raster_dpi: Resolution,
+    pageno: int,
+    page_dpi: Resolution = None,
+    rotation: int = None,
+    filter_vector: bool = False,
+) -> None:
+    """Rasterize one page of a PDF at resolution raster_dpi in canvas units.
+
+    The image is sized to match the integer pixels dimensions implied by
+    raster_dpi even if those numbers are noninteger. The image's DPI will
+    be overridden with the values in page_dpi.
+
+    Args:
+        raster_device: type of image to produce at output_file
+        raster_dpi: resolution 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
+    Returns:
+        None
+    """
+
+
 @hookspec(firstresult=True)
 def filter_ocr_image(page: 'PageContext', image: Image) -> Image:
     """Called to filter the image before it is sent to OCR.
diff --git a/tests/test_main.py b/tests/test_main.py
index 6f9d7b50..0b913a14 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -39,7 +39,6 @@ from ocrmypdf.pdfinfo import Colorspace, Encoding, PdfInfo
 check_ocrmypdf = pytest.helpers.check_ocrmypdf
 run_ocrmypdf = pytest.helpers.run_ocrmypdf
 run_ocrmypdf_api = pytest.helpers.run_ocrmypdf_api
-spoof = pytest.helpers.spoof
 
 
 RENDERERS = ['hocr', 'sandwich']
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index 59250eac..16175140 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -47,7 +47,6 @@ pytestmark = pytest.mark.filterwarnings('ignore:.*XMLParser.*:DeprecationWarning
 
 check_ocrmypdf = pytest.helpers.check_ocrmypdf
 run_ocrmypdf = pytest.helpers.run_ocrmypdf
-spoof = pytest.helpers.spoof
 
 
 @pytest.mark.parametrize("output_type", ['pdfa', 'pdf'])
diff --git a/tests/test_validation.py b/tests/test_validation.py
index f6fcc775..3e6272af 100644
--- a/tests/test_validation.py
+++ b/tests/test_validation.py
@@ -29,19 +29,29 @@ from ocrmypdf.exceptions import BadArgsError, MissingDependencyError
 from ocrmypdf.pdfinfo import PdfInfo
 
 
-def make_opts(input_file='a.pdf', output_file='b.pdf', language='eng', **kwargs):
+def make_opts_pm(input_file='a.pdf', output_file='b.pdf', language='eng', **kwargs):
     if language is not None:
         kwargs['language'] = language
     parser = get_parser()
     pm = get_plugin_manager(kwargs.get('plugins', []))
     pm.hook.add_options(parser=parser)
-    return create_options(
-        input_file=input_file, output_file=output_file, parser=parser, **kwargs
+    return (
+        create_options(
+            input_file=input_file, output_file=output_file, parser=parser, **kwargs
+        ),
+        pm,
     )
 
 
+def make_opts(*args, **kwargs):
+    opts, _pm = make_opts_pm(*args, **kwargs)
+    return opts
+
+
 def test_hocr_notlatin_warning(caplog):
-    vd.check_options_output(make_opts(language='chi_sim', pdf_renderer='hocr'))
+    vd.check_options(
+        *make_opts_pm(language='chi_sim', pdf_renderer='hocr', output_type='pdfa')
+    )
     assert 'PDF renderer is known to cause' in caplog.text
 
 
@@ -49,20 +59,20 @@ def test_old_ghostscript(caplog):
     with patch('ocrmypdf.exec.ghostscript.version', return_value='9.19'), patch(
         'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
     ):
-        vd.check_options_output(make_opts(language='chi_sim', output_type='pdfa'))
+        vd.check_options(*make_opts_pm(language='chi_sim', output_type='pdfa'))
         assert 'Ghostscript does not work correctly' in caplog.text
 
     with patch('ocrmypdf.exec.ghostscript.version', return_value='9.18'), patch(
         'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
     ):
         with pytest.raises(MissingDependencyError):
-            vd.check_options_output(make_opts(output_type='pdfa-3'))
+            vd.check_options(*make_opts_pm(output_type='pdfa-3'))
 
     with patch('ocrmypdf.exec.ghostscript.version', return_value='9.24'), patch(
         'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
     ):
         with pytest.raises(MissingDependencyError):
-            vd.check_dependency_versions(make_opts())
+            vd.check_options(*make_opts_pm())
 
 
 def test_old_tesseract_error():
@@ -97,7 +107,6 @@ def test_optimizing(caplog):
 
 
 def test_user_words(caplog):
-
     with patch('ocrmypdf.exec.tesseract.has_user_words', return_value=False):
         opts = make_opts(user_words='foo')
         plugin_manager = get_plugin_manager(opts.plugins)