diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33ce8a2..d352048 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,23 @@ Pre-v1.0.0 tags followed the pi npm version (`v{pi_version}[letter]`).
 
 ---
 
+## Unreleased
+
+### Fixed
+
+- **`pandoc --pdf-engine=typst` now works without `-V mainfont`.** pandoc's
+  bundled typst template (`/usr/share/pandoc/data/templates/template.typst`)
+  defaults the document font to an empty tuple (`font: ()`), so a naked
+  `pandoc --pdf-engine=typst` (and `studio_export_pdf` in some cases) failed
+  with `error: font fallback list must not be empty` unless the caller passed
+  `-V mainfont="..."`. The base now patches that template default to
+  `Libertinus Serif` (typst's own bundled default font) at build time, so PDF
+  export works out of the box. Base-affecting (`Dockerfile.base` RUN), rebuilds
+  `base-<hash>`. README gains a "Generating a PDF with pandoc + typst" section
+  with the working command and how to override the font via `-V mainfont`.
+
+---
+
 ## v1.4.0 — 2026-07-11
 
 Minor release. Headline: **PDF export works out of the box** — the base now
diff --git a/Dockerfile.base b/Dockerfile.base
index ebc67f1..1da872c 100644
--- a/Dockerfile.base
+++ b/Dockerfile.base
@@ -14,7 +14,7 @@
 # content-addressed over this file, so any byte change invalidates the
 # cache. Recommended cadence: once per release for security updates.
 #
-# BASE_REBUILD_DATE: 2026-07-11 (Unreleased — typst PDF engine + xz-utils)
+# BASE_REBUILD_DATE: 2026-07-11 (Unreleased — typst PDF engine + xz-utils + pandoc typst-template default-font patch)
 #
 # ── Lineage note ─────────────────────────────────────────────────────
 # Adapted from opencode-devbox/Dockerfile.base (commit before v1.16.2).
@@ -465,6 +465,13 @@ RUN ARCH=$(case "${TARGETARCH}" in amd64) echo "x86_64" ;; arm64) echo "aarch64"
 # typst ships a `.tar.xz` asset (hence xz-utils in the apt layer above)
 # that extracts to typst-<arch>-unknown-linux-musl/typst. Pin a specific
 # tag with --build-arg TYPST_VERSION=vX.Y.Z.
+#
+# We also patch pandoc's bundled typst template
+# (/usr/share/pandoc/data/templates/template.typst): its conf() defaults the
+# document font to an empty tuple (`font: ()`), so a naked
+# `pandoc --pdf-engine=typst` fails with "font fallback list must not be empty"
+# unless the caller passes `-V mainfont=...`. We default it to Libertinus Serif
+# (typst's own bundled default font) so PDF export works out-of-the-box.
 ARG TYPST_VERSION=latest
 RUN ARCH=$(case "${TARGETARCH}" in amd64) echo "x86_64" ;; arm64) echo "aarch64" ;; *) echo "x86_64" ;; esac) && \
     V="${TYPST_VERSION}" && \
@@ -476,7 +483,9 @@ RUN ARCH=$(case "${TARGETARCH}" in amd64) echo "x86_64" ;; arm64) echo "aarch64"
     curl -fsSL --retry 5 --retry-delay 5 --retry-all-errors "https://github.com/typst/typst/releases/download/v${V}/typst-${ARCH}-unknown-linux-musl.tar.xz" | tar -xJ -C /tmp && \
     install /tmp/typst-${ARCH}-unknown-linux-musl/typst /usr/local/bin/typst && \
     rm -rf /tmp/typst-${ARCH}-unknown-linux-musl && \
-    typst --version
+    typst --version && \
+    sed -i 's/^  font: (),$/  font: ("Libertinus Serif",),/' /usr/share/pandoc/data/templates/template.typst && \
+    grep -q 'font: ("Libertinus Serif",),' /usr/share/pandoc/data/templates/template.typst
 
 # ── yq (mikefarah) — YAML processor, jq's companion for YAML ─────────
 # Installed as the mikefarah Go binary — NOT Debian's `yq` apt package, which
diff --git a/README.md b/README.md
index 655e9b8..b2bfae6 100644
--- a/README.md
+++ b/README.md
@@ -292,6 +292,26 @@ Assuming the compose file publishes `127.0.0.1:8765:8765` (see method B):
 > LaTeX-exact output you can install `texlive-xetex` on demand as a heavier
 > fallback. HTML export, KaTeX, Mermaid, and all REPL features work regardless.
 
+### Generating a PDF with pandoc + typst
+
+The base ships `pandoc` (front-end) and `typst` (PDF engine), so Markdown → PDF
+works out of the box:
+
+```bash
+pandoc doc.md --pdf-engine=typst -o doc.pdf
+```
+
+The base patches pandoc's bundled typst template so it defaults to the
+**Libertinus Serif** font. Without that patch a naked `--pdf-engine=typst`
+fails with `error: font fallback list must not be empty`, because the upstream
+template leaves the font unset. To pick a different face, pass one of the fonts
+typst can see (`typst fonts` lists them — DejaVu Serif/Sans/Mono, Libertinus
+Serif, New Computer Modern):
+
+```bash
+pandoc doc.md --pdf-engine=typst -V mainfont="New Computer Modern" -o doc.pdf
+```
+
 ### Graphviz diagrams in Studio: `dot-watch`
 
 pi-studio renders **Mermaid** natively but has **no Graphviz/DOT renderer**.