diff --git a/doc/build-latexusage-pdf.py b/doc/build-latexusage-pdf.py
index f8dd05446..357da73e5 100644
--- a/doc/build-latexusage-pdf.py
+++ b/doc/build-latexusage-pdf.py
@@ -39,9 +39,11 @@ def main():
     args = parse_args()
     buildroot_path = pathlib.Path(args.build_dir)
     clean_artifacts(buildroot_path, args.latexusage_name)
+
+    buildroot_path_str = str(buildroot_path.as_posix())
     pdflatex_base_args = [
         args.pdflatex_executable,
-        f"-output-directory={str(buildroot_path)}",
+        f"-output-directory={buildroot_path_str}",
     ]
     asy_base_dir = pathlib.Path(args.asy_base_dir)
     asy_base_args = [