diff --git a/dangerzone/document.py b/dangerzone/document.py
index 681202f54..267dea7ee 100644
--- a/dangerzone/document.py
+++ b/dangerzone/document.py
@@ -64,5 +64,5 @@ def output_filename(self, filename: str) -> None:
 
 
 class DocumentFilenameException(Exception):
-    def __init__(self, message):
+    def __init__(self, message: str) -> None:
         super().__init__(message)
diff --git a/tests/__init__.py b/tests/__init__.py
index cad40abc7..bb7683f58 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -20,3 +20,8 @@
 
 class TestBase:
     sample_doc = str(test_docs_dir.joinpath(BASIC_SAMPLE))
+
+
+@pytest.fixture
+def sample_doc():
+    return str(test_docs_dir.joinpath(BASIC_SAMPLE))
diff --git a/tests/test_cli.py b/tests/test_cli.py
index f39a98d50..c4d5dec39 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-import os
 import shutil
 import tempfile
+from pathlib import Path
 
 import pytest
 from click.testing import CliRunner, Result
@@ -92,7 +92,7 @@ def test_lang_eng(self):
     )
     def test_filenames(self, filename):
         tempdir = tempfile.mkdtemp(prefix="dangerzone-")
-        doc_path = os.path.join(filename)
+        doc_path = str(Path(tempdir).joinpath(filename))
         shutil.copyfile(self.sample_doc, doc_path)
         result = self.run_cli(doc_path)
         shutil.rmtree(tempdir)
diff --git a/tests/test_document.py b/tests/test_document.py
new file mode 100644
index 000000000..a00b10c64
--- /dev/null
+++ b/tests/test_document.py
@@ -0,0 +1,87 @@
+import os
+import tempfile
+
+import pytest
+
+from dangerzone.document import DocumentFilenameException, DocumentHolder
+
+from . import sample_doc
+
+
+@pytest.fixture
+def unwriteable_pdf():
+    file_path = tempfile.mktemp(suffix=".pdf")
+    with open(file_path, "w+"):
+        # create file
+        pass
+    os.chmod(file_path, mode=600)
+    return file_path
+
+
+@pytest.fixture
+def unreadable_pdf():
+    file_path = tempfile.mktemp(suffix=".pdf")
+    with open(file_path, "w+"):
+        # create file
+        pass
+    os.chmod(file_path, mode=0)
+    return file_path
+
+
+def test_input_sample_init(sample_doc):
+    DocumentHolder(sample_doc)
+
+
+def test_input_sample_after(sample_doc):
+    d = DocumentHolder()
+    d.input_filename = sample_doc
+
+
+def test_input_file_none():
+    """
+    Attempts to read a document's filename when no doc has been set
+    """
+    d = DocumentHolder()
+    with pytest.raises(DocumentFilenameException):
+        d.input_filename
+
+
+def test_input_file_non_existing():
+    with pytest.raises(DocumentFilenameException):
+        DocumentHolder("fake-dir/non-existing-file.pdf")
+
+
+def test_input_file_unreadable(unreadable_pdf):
+    with pytest.raises(DocumentFilenameException):
+        DocumentHolder(unreadable_pdf)
+
+
+def test_output_file_unwriteable(unwriteable_pdf):
+    d = DocumentHolder()
+    with pytest.raises(DocumentFilenameException):
+        d.output_filename = unwriteable_pdf
+
+
+def test_output():
+    pdf_file = tempfile.mktemp(suffix=".pdf")
+    d = DocumentHolder()
+    d.output_filename = pdf_file
+
+
+def test_output_file_none():
+    """
+    Attempts to read a document's filename when no doc has been set
+    """
+    d = DocumentHolder()
+    with pytest.raises(DocumentFilenameException):
+        d.output_filename(self, filename)
+
+
+def test_output_file_not_pdf():
+    docx_file = tempfile.mktemp(suffix=".docx")
+    d = DocumentHolder()
+
+    with pytest.raises(DocumentFilenameException):
+        d.output_filename = docx_file
+
+    assert not os.path.exists(docx_file)