diff --git a/pyproject.toml b/pyproject.toml
index 69c65ec017..74fbef9d9e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -153,7 +153,7 @@ preprocessing = [
 file-conversion = [
   "azure-ai-formrecognizer>=3.2.0b2",  # Microsoft Azure's Form Recognizer service (text and table exctrator)
   "python-docx",
-  "python-pptx",
+  "python-pptx<=1.0",
   "tika",  # Apache Tika (text & metadata extractor)
   "beautifulsoup4",
   "markdown",