diff --git a/HISTORY.md b/HISTORY.md
index e80269f..0f7f6ce 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,9 @@
 # History
 
+## 0.15.2 (2025-01-23)
+
+* Removes running in a ProcessPoolExecutor
+
 ## 0.15.1 (2025-01-23)
 
 * Fix potential memory leaks by confining use of `pyvips` to subprocesses
diff --git a/panimg/image_builders/tiff.py b/panimg/image_builders/tiff.py
index 81c22dd..3a8afeb 100644
--- a/panimg/image_builders/tiff.py
+++ b/panimg/image_builders/tiff.py
@@ -2,7 +2,6 @@
 import re
 from collections import defaultdict
 from collections.abc import Callable, Iterator
-from concurrent.futures import ProcessPoolExecutor
 from dataclasses import dataclass, field
 from pathlib import Path
 from tempfile import TemporaryDirectory
@@ -325,13 +324,11 @@ def _convert(
             if associated_files_getter:
                 associated_files = associated_files_getter(gc_file.path)
 
-            with ProcessPoolExecutor(max_workers=1) as executor:
-                tiff_file = executor.submit(
-                    _convert_to_tiff,
-                    path=file,
-                    pk=gc_file.pk,
-                    output_directory=output_directory,
-                ).result()
+            tiff_file = _convert_to_tiff(
+                path=file,
+                pk=gc_file.pk,
+                output_directory=output_directory,
+            )
         except Exception as e:
             file_errors[file].append(
                 format_error(
diff --git a/panimg/post_processors/tiff_to_dzi.py b/panimg/post_processors/tiff_to_dzi.py
index fe5fdd9..3a4fde0 100644
--- a/panimg/post_processors/tiff_to_dzi.py
+++ b/panimg/post_processors/tiff_to_dzi.py
@@ -1,5 +1,4 @@
 import logging
-from concurrent.futures import ProcessPoolExecutor
 
 from panimg.models import ImageType, PanImgFile, PostProcessorResult
 from panimg.settings import DZI_TILE_SIZE
@@ -13,10 +12,7 @@ def tiff_to_dzi(*, image_files: set[PanImgFile]) -> PostProcessorResult:
     for file in image_files:
         if file.image_type == ImageType.TIFF:
             try:
-                with ProcessPoolExecutor(max_workers=1) as executor:
-                    result = executor.submit(
-                        _create_dzi_image, tiff_file=file
-                    ).result()
+                result = _create_dzi_image(tiff_file=file)
             except Exception as e:
                 logger.warning(f"Could not create DZI for {file}: {e}")
                 continue
diff --git a/pyproject.toml b/pyproject.toml
index 9f85850..b7c7080 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "panimg"
-version = "0.15.1"
+version = "0.15.2"
 description = "Conversion of medical images to MHA and TIFF."
 license = "Apache-2.0"
 authors = ["James Meakin <panimg@jmsmkn.com>"]