diff --git a/.github/workflows/build-fastremap.yml b/.github/workflows/build-fastremap.yml
index 887490f06cb6..5fc515467d81 100644
--- a/.github/workflows/build-fastremap.yml
+++ b/.github/workflows/build-fastremap.yml
@@ -16,11 +16,13 @@ on:
     paths:
       - '.github/workflows/build-fastremap.yml'
       - 'docs/packages/fastremap.yaml'
+      - 'patches/fastremap/**'
   push:
     branches: [main]
     paths:
       - '.github/workflows/build-fastremap.yml'
       - 'docs/packages/fastremap.yaml'
+      - 'patches/fastremap/**'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
@@ -62,6 +64,17 @@ jobs:
           ref: ${{ env.FASTREMAP_VERSION }}
           persist-credentials: false
 
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      # meson-python (upstream's backend since 1.21.0) only ships the files named
+      # in `license-files`; see patches/fastremap/1.21.0 for details.
+      - name: Apply patches
+        run: git apply python-wheels/patches/fastremap/${{ env.FASTREMAP_VERSION }}/*.patch
+
       - uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
         with:
           output-dir: wheelhouse/
diff --git a/docs/packages/fastremap.yaml b/docs/packages/fastremap.yaml
index e6a6bff205ab..54b3605b03dd 100644
--- a/docs/packages/fastremap.yaml
+++ b/docs/packages/fastremap.yaml
@@ -17,3 +17,4 @@ versions:
   - filename: fastremap-1.20.0-cp314-cp314t-manylinux_2_34_riscv64.manylinux_2_39_riscv64.whl
     sha256: 7162d4ac10ac2dbd0909e4cb83b4e598c4d0306be19026fc0261981a1993fbb3
     requires-python: '>=3.9,<4.0'
+- version: 1.21.0
diff --git a/patches/fastremap/1.21.0/0001-ship-the-LICENSE-and-AUTHORS-files-in-the-wheel-s-di.patch b/patches/fastremap/1.21.0/0001-ship-the-LICENSE-and-AUTHORS-files-in-the-wheel-s-di.patch
new file mode 100644
index 000000000000..834a553f44b6
--- /dev/null
+++ b/patches/fastremap/1.21.0/0001-ship-the-LICENSE-and-AUTHORS-files-in-the-wheel-s-di.patch
@@ -0,0 +1,30 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Thu, 22 Oct 2026 12:00:00 +0200
+Subject: [PATCH] ship the LICENSE and AUTHORS files in the wheel's dist-info
+
+Since 1.21.0 the build backend is meson-python, which only copies the files
+named in `license-files` and has no implicit LICEN[CS]E*/AUTHORS* fallback
+(setuptools, used up to 1.20.0, did). With the legacy `license = { text = }`
+table and no `license-files`, the wheel carries no LICENSE at all.
+
+pyproject-metadata only accepts `license-files` next to an SPDX expression,
+so `LGPL-3.0` (a deprecated identifier) becomes its replacement
+`LGPL-3.0-only`, the same licence.
+
+Upstream-Status: To upstream [not yet submitted; no fork of seung-lab/fastremap to push from]
+---
+diff --git a/pyproject.toml b/pyproject.toml
+index 38983ff..e748e79 100644
+--- a/pyproject.toml
++++ b/pyproject.toml
+@@ -13,7 +13,8 @@ dynamic = ["version"]
+ description = 'Remap, mask, renumber, unique, and in-place transposition of 3D labeled images. Point cloud too.'
+ readme = { file = 'README.md', content-type = 'text/markdown' }
+ requires-python = '>=3.9,<4.0'
+-license = { text = 'LGPL-3.0' }
++license = 'LGPL-3.0-only'
++license-files = ['LICENSE', 'AUTHORS']
+ authors = [
+   { name = 'William Silversmith', email = 'ws9@princeton.edu' },
+ ]