diff -pruN 0.4.52+ds-3/debian/changelog 0.4.52+ds-4/debian/changelog
--- 0.4.52+ds-3/debian/changelog	2025-09-24 18:59:22.000000000 +0000
+++ 0.4.52+ds-4/debian/changelog	2025-10-04 12:52:05.000000000 +0000
@@ -1,3 +1,10 @@
+mdbook (0.4.52+ds-4) unstable; urgency=medium
+
+  * Team upload.
+  * Add patch to support pulldown-cmark 0.13
+
+ -- Peter Michael Green <plugwash@debian.org>  Sat, 04 Oct 2025 12:52:05 +0000
+
 mdbook (0.4.52+ds-3) unstable; urgency=medium
 
   [ NoisyCoil ]
diff -pruN 0.4.52+ds-3/debian/control 0.4.52+ds-4/debian/control
--- 0.4.52+ds-3/debian/control	2025-09-24 17:37:51.000000000 +0000
+++ 0.4.52+ds-4/debian/control	2025-10-04 12:52:05.000000000 +0000
@@ -25,7 +25,7 @@ Build-Depends-Arch:
  librust-once-cell-dev,
  librust-opener-dev,
  librust-pathdiff-dev,
- librust-pulldown-cmark-dev,
+ librust-pulldown-cmark-0.13-dev,
  librust-regex-dev,
  librust-select-dev,
  librust-serde-dev,
@@ -102,7 +102,7 @@ Depends: ${misc:Depends},
  librust-once-cell-dev,
  librust-opener-dev,
  librust-pathdiff-dev,
- librust-pulldown-cmark-dev,
+ librust-pulldown-cmark-0.13-dev,
  librust-regex-dev,
  librust-serde-dev,
  librust-serde+derive-dev,
diff -pruN 0.4.52+ds-3/debian/patches/pulldown-cmark-0.13.patch 0.4.52+ds-4/debian/patches/pulldown-cmark-0.13.patch
--- 0.4.52+ds-3/debian/patches/pulldown-cmark-0.13.patch	1970-01-01 00:00:00.000000000 +0000
+++ 0.4.52+ds-4/debian/patches/pulldown-cmark-0.13.patch	2025-10-04 12:52:05.000000000 +0000
@@ -0,0 +1,43 @@
+This patch is based on the upstream commit described below, adapted for use
+in the upstream package by Peter Michael Green.
+
+commit 91f04bc7bae2fb56ae11e3086553c4fdb0b68da0
+Author: Roms1383 <romain.kelifa@gmail.com>
+Date:   Sun Jun 16 10:16:10 2024 +0700
+
+    Upgrade pulldown-cmark to 0.13.0
+
+diff --git a/Cargo.toml b/Cargo.toml
+index f027a20a..69af69a8 100644
+--- a/Cargo.toml
++++ b/Cargo.toml
+@@ -51,1 +51,1 @@
+-pulldown-cmark = { version = "0.10.0", default-features = false, features = ["html"] } # Do not update, part of the public api.
++pulldown-cmark = { version = "0.13.0", default-features = false, features = ["html"] } # Do not update, part of the public api.
+diff --git a/examples/remove-emphasis/mdbook-remove-emphasis/Cargo.toml b/examples/remove-emphasis/mdbook-remove-emphasis/Cargo.toml
+index 1b55e291..8b2edd03 100644
+--- a/examples/remove-emphasis/mdbook-remove-emphasis/Cargo.toml
++++ b/examples/remove-emphasis/mdbook-remove-emphasis/Cargo.toml
+@@ -5,2 +5,2 @@
+-pulldown-cmark = { version = "0.12.2", default-features = false }
+-pulldown-cmark-to-cmark = "18.0.0"
++pulldown-cmark = { workspace = true, default-features = false }
++pulldown-cmark-to-cmark = "21.0.0"
+diff --git a/src/renderer/html_handlebars/search.rs b/src/renderer/html_handlebars/search.rs
+index 0c067905..b14c9c67 100644
+--- a/src/renderer/html_handlebars/search.rs
++++ b/src/renderer/html_handlebars/search.rs
+@@ -200,6 +200,13 @@ fn render_item(
+                 // blocks, and worse case you have some noise in the index.
+                 body.push_str(&clean_html(&html));
+             }
++            Event::InlineMath(text) | Event::DisplayMath(text) => {
++                if in_heading {
++                    heading.push_str(&text);
++                } else {
++                    body.push_str(&text);
++                }
++            }
+             Event::Start(_) | Event::End(_) | Event::Rule | Event::SoftBreak | Event::HardBreak => {
+                 // Insert spaces where HTML output would usually separate text
+                 // to ensure words don't get merged together
diff -pruN 0.4.52+ds-3/debian/patches/series 0.4.52+ds-4/debian/patches/series
--- 0.4.52+ds-3/debian/patches/series	2025-09-24 17:37:51.000000000 +0000
+++ 0.4.52+ds-4/debian/patches/series	2025-10-04 12:52:05.000000000 +0000
@@ -4,3 +4,4 @@ disable-snapbox.patch
 disable-mathjax.patch
 remove-excluded.patch
 disable-example-remove-emphasis.patch
+pulldown-cmark-0.13.patch