diff --git a/dangerzone/isolation_provider/dummy.py b/dangerzone/isolation_provider/dummy.py
index 80dd17fcf..9ebc345fa 100644
--- a/dangerzone/isolation_provider/dummy.py
+++ b/dangerzone/isolation_provider/dummy.py
@@ -1,18 +1,25 @@
 import logging
-import os
-import shutil
 import subprocess
 import sys
-import time
-from typing import Callable, Optional
 
+from ..conversion.common import DangerzoneConverter
 from ..document import Document
-from ..util import get_resource_path
 from .base import IsolationProvider, terminate_process_group
 
 log = logging.getLogger(__name__)
 
 
+def dummy_script() -> None:
+    sys.stdin.buffer.read()
+    pages = 2
+    width = height = 9
+    DangerzoneConverter._write_int(pages)
+    for page in range(pages):
+        DangerzoneConverter._write_int(width)
+        DangerzoneConverter._write_int(height)
+        DangerzoneConverter._write_bytes(width * height * 3 * b"A")
+
+
 class Dummy(IsolationProvider):
     """Dummy Isolation Provider (FOR TESTING ONLY)
 
@@ -32,51 +39,15 @@ def __init__(self) -> None:
     def install(self) -> bool:
         return True
 
-    def convert(
-        self,
-        document: Document,
-        ocr_lang: Optional[str],
-        progress_callback: Optional[Callable] = None,
-    ) -> None:
-        self.progress_callback = None
-        log.debug("Dummy converter started:")
-        log.debug(
-            f"  - document: {os.path.basename(document.input_filename)} ({document.id})"
-        )
-        log.debug(f"  - ocr     : {ocr_lang}")
-        log.debug("\n(simulating conversion)")
-        success = True
-        progress = [
-            [False, "Converting to PDF using GraphicsMagick", 0.0],
-            [False, "Separating document into pages", 3.0],
-            [False, "Converting page 1/1 to pixels", 5.0],
-            [False, "Converted document to pixels", 50.0],
-            [False, "Converting page 1/1 from pixels to PDF", 50.0],
-            [False, "Merging 1 pages into a single PDF", 95.0],
-            [False, "Compressing PDF", 97.0],
-            [False, "Safe PDF created", 100.0],
-        ]
-        for error, text, percentage in progress:
-            self.print_progress(document, error, text, percentage)  # type: ignore [arg-type]
-            if error:
-                success = False
-        if success:
-            shutil.copy(
-                get_resource_path("dummy_document.pdf"), document.output_filename
-            )
-        document.mark_as_safe()
-        if document.archive_after_conversion:
-            document.archive()
-
-    def pixels_to_pdf(
-        self, document: Document, tempdir: str, ocr_lang: Optional[str]
-    ) -> None:
-        pass
-
     def start_doc_to_pixels_proc(self, document: Document) -> subprocess.Popen:
-        dummy_cmd = ["python3", "-c", "print('The cake is a lie')"]
+        cmd = [
+            sys.executable,
+            "-c",
+            "from dangerzone.isolation_provider.dummy import dummy_script;"
+            " dummy_script()",
+        ]
         return subprocess.Popen(
-            dummy_cmd,
+            cmd,
             stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
             stderr=self.proc_stderr,
diff --git a/tests/isolation_provider/test_dummy.py b/tests/isolation_provider/test_dummy.py
index 100268769..198a6afb1 100644
--- a/tests/isolation_provider/test_dummy.py
+++ b/tests/isolation_provider/test_dummy.py
@@ -1,11 +1,9 @@
 import os
-import subprocess
 
 import pytest
 from pytest_mock import MockerFixture
 
 from dangerzone.conversion import errors
-from dangerzone.document import Document
 from dangerzone.isolation_provider.base import IsolationProvider
 from dangerzone.isolation_provider.dummy import Dummy
 
@@ -16,24 +14,6 @@
     pytest.skip("Dummy conversion is not enabled", allow_module_level=True)
 
 
-class DummyWait(Dummy):
-    """Dummy isolation provider that spawns a blocking process."""
-
-    def start_doc_to_pixels_proc(self, document: Document) -> subprocess.Popen:
-        return subprocess.Popen(
-            ["python3"],
-            stdin=subprocess.PIPE,
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
-            start_new_session=True,
-        )
-
-
-@pytest.fixture
-def provider_wait() -> DummyWait:
-    return DummyWait()
-
-
 @pytest.fixture
 def provider() -> Dummy:
     return Dummy()
@@ -42,21 +22,12 @@ def provider() -> Dummy:
 class TestDummyTermination(IsolationProviderTermination):
     def test_failed(
         self,
-        provider_wait: IsolationProvider,
+        provider: IsolationProvider,
         mocker: MockerFixture,
     ) -> None:
         mocker.patch.object(
-            provider_wait,
+            provider,
             "get_proc_exception",
             return_value=errors.DocFormatUnsupported(),
         )
-        super().test_failed(provider_wait, mocker)
-
-    def test_linger_unkillable(
-        self,
-        provider_wait: IsolationProvider,
-        mocker: MockerFixture,
-    ) -> None:
-        # We have to spawn a blocking process here, else we can't imitate an
-        # "unkillable" process.
-        super().test_linger_unkillable(provider_wait, mocker)
+        super().test_failed(provider, mocker)