diff --git a/src/ocrmypdf/_validation.py b/src/ocrmypdf/_validation.py
index 6dc0566b..76f9b7a4 100644
--- a/src/ocrmypdf/_validation.py
+++ b/src/ocrmypdf/_validation.py
@@ -28,7 +28,13 @@ from ocrmypdf.exceptions import (
     MissingDependencyError,
     OutputFileAccessError,
 )
-from ocrmypdf.helpers import is_file_writable, monotonic, safe_symlink
+from ocrmypdf.helpers import (
+    is_file_writable,
+    monotonic,
+    running_in_docker,
+    running_in_snap,
+    safe_symlink,
+)
 from ocrmypdf.subprocess import check_external_program
 
 log = logging.getLogger(__name__)
@@ -237,18 +243,6 @@ def check_options(options: Namespace, plugin_manager: PluginManager) -> None:
     _check_plugin_options(options, plugin_manager)
 
 
-def _in_docker():
-    return Path('/.dockerenv').exists()
-
-
-def _in_snap():
-    try:
-        cgroup_text = Path('/proc/self/cgroup').read_text()
-        return 'snap.ocrmypdf' in cgroup_text
-    except FileNotFoundError:
-        return False
-
-
 def create_input_file(options: Namespace, work_folder: Path) -> tuple[Path, str]:
     if options.input_file == '-':
         # stdin
@@ -272,7 +266,7 @@ def create_input_file(options: Namespace, work_folder: Path) -> tuple[Path, str]
             return target, os.fspath(options.input_file)
         except FileNotFoundError as e:
             msg = f"File not found - {options.input_file}"
-            if _in_docker():  # pragma: no cover
+            if running_in_docker():  # pragma: no cover
                 msg += (
                     "\nDocker cannot access your working directory unless you "
                     "explicitly share it with the Docker container and set up"
@@ -282,7 +276,7 @@ def create_input_file(options: Namespace, work_folder: Path) -> tuple[Path, str]
                     "\tdocker run -i --rm jbarlow83/ocrmypdf - - <input.pdf >output.pdf"
                     "\n"
                 )
-            elif _in_snap():  # pragma: no cover
+            elif running_in_snap():  # pragma: no cover
                 msg += (
                     "\nSnap applications cannot access files outside of "
                     "your home directory unless you explicitly allow it. "
diff --git a/src/ocrmypdf/helpers.py b/src/ocrmypdf/helpers.py
index 6402e951..a8b421be 100644
--- a/src/ocrmypdf/helpers.py
+++ b/src/ocrmypdf/helpers.py
@@ -335,3 +335,17 @@ def pikepdf_enable_mmap() -> None:
         )
     except AttributeError:
         log.debug("pikepdf mmap not available")
+
+
+def running_in_docker() -> bool:
+    """Returns True if we seem to be running in a Docker container."""
+    return Path('/.dockerenv').exists()
+
+
+def running_in_snap() -> bool:
+    """Returns True if we seem to be running in a Snap container."""
+    try:
+        cgroup_text = Path('/proc/self/cgroup').read_text()
+        return 'snap.ocrmypdf' in cgroup_text
+    except FileNotFoundError:
+        return False
diff --git a/tests/conftest.py b/tests/conftest.py
index c3a74850..004d91df 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -24,11 +24,6 @@ def is_macos():
     return platform.system() == 'Darwin'
 
 
-def running_in_docker():
-    # Docker creates a file named /.dockerenv in all supported versions
-    return Path('/.dockerenv').exists()
-
-
 def have_unpaper():
     try:
         unpaper.version()
diff --git a/tests/test_completion.py b/tests/test_completion.py
index aff017fd..f8462a9e 100644
--- a/tests/test_completion.py
+++ b/tests/test_completion.py
@@ -8,7 +8,7 @@ from subprocess import run
 
 import pytest
 
-from .conftest import running_in_docker
+from ocrmypdf.helpers import running_in_docker
 
 pytestmark = pytest.mark.skipif(
     running_in_docker(),
diff --git a/tests/test_helpers.py b/tests/test_helpers.py
index b4cb541d..058c339c 100644
--- a/tests/test_helpers.py
+++ b/tests/test_helpers.py
@@ -13,8 +13,7 @@ import pytest
 from packaging.version import Version
 
 from ocrmypdf import helpers
-
-from .conftest import running_in_docker
+from ocrmypdf.helpers import running_in_docker
 
 needs_symlink = pytest.mark.skipif(os.name == 'nt', reason='needs posix symlink')
 windows_only = pytest.mark.skipif(os.name != 'nt', reason="Windows test")
diff --git a/tests/test_main.py b/tests/test_main.py
index a6b40622..c7f051b6 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -18,6 +18,7 @@ from PIL import Image
 import ocrmypdf
 from ocrmypdf._exec import tesseract
 from ocrmypdf.exceptions import ExitCode, MissingDependencyError
+from ocrmypdf.helpers import running_in_docker
 from ocrmypdf.pdfa import file_claims_pdfa
 from ocrmypdf.pdfinfo import Colorspace, Encoding, PdfInfo
 from ocrmypdf.subprocess import get_version
@@ -29,7 +30,6 @@ from .conftest import (
     is_macos,
     run_ocrmypdf,
     run_ocrmypdf_api,
-    running_in_docker,
 )
 
 # pylint: disable=redefined-outer-name