diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 0e3cf21..d60792e 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -39,6 +39,11 @@ jobs:
         with:
           python-version: '3.12'
 
+      # pyscard has no manylinux wheels, so it builds from source on Linux
+      # and needs the PC/SC development headers.
+      - name: Install the PC/SC development headers
+        run: sudo apt-get update && sudo apt-get install -y libpcsclite-dev
+
       - name: Install pysim and the test dependencies
         working-directory: simple
         run: |
diff --git a/README.md b/README.md
index 4c68b93..344b478 100644
--- a/README.md
+++ b/README.md
@@ -739,7 +739,7 @@ The bundled Python server wraps [pySim](https://osmocom.org/projects/pysim/wiki)
 ### Prerequisites
 
 - **Python 3.9+** with `pip`, and **Git**
-- **Smart card reader** (PC/SC or serial/FTDI) — PC/SC is preferable (`pcsc-lite` + `ccid` on Linux)
+- **Smart card reader** (PC/SC or serial/FTDI) — PC/SC is preferable (`pcsc-lite` + `ccid` on Linux). `pyscard` has no Linux wheels, so it builds from source: install the PC/SC header package too (`libpcsclite-dev` on Debian/Ubuntu, `pcsc-lite-devel` on Fedora; on Arch `pcsclite` includes them).
 - **Windows** — use Python 3.9–3.13 (3.13 recommended): `pyscard` ships precompiled wheels for these versions. On 3.14 it builds from source (needs MSVC C++ Build Tools). The SMPP bridge (`smpp.twisted3`) is intentionally skipped on Windows.
 
 ### Scripts
diff --git a/README_RUS.md b/README_RUS.md
index adfecaa..69c63ff 100644
--- a/README_RUS.md
+++ b/README_RUS.md
@@ -723,7 +723,7 @@ PWA проверяет версию сервера при подключении
 ### Требования
 
 - **Python 3.9+** с `pip`, и **Git**
-- **Смарт-картридер** (PC/SC или serial/FTDI) — предпочтителен PC/SC (`pcsc-lite` + `ccid` на Linux)
+- **Смарт-картридер** (PC/SC или serial/FTDI) — предпочтителен PC/SC (`pcsc-lite` + `ccid` на Linux). У `pyscard` нет Linux-wheel, поэтому он собирается из исходников: поставьте и пакет с заголовками PC/SC (`libpcsclite-dev` в Debian/Ubuntu, `pcsc-lite-devel` в Fedora; в Arch они входят в `pcsclite`).
 - **Windows** — используйте Python 3.9–3.13 (рекомендуется 3.13): у `pyscard` есть готовые wheel. На 3.14 он собирается из исходников (нужны MSVC C++ Build Tools). SMPP-мост (`smpp.twisted3`) в Windows сознательно не ставится.
 
 ### Скрипты
diff --git a/frontend/index.html b/frontend/index.html
index d3db992..9821436 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -1943,7 +1943,7 @@
 // ===== Version =====
 // Single source of truth for the PWA version: shown in the header and used
 // by the server version check in pysimConnect().
-const SIMPLE_VERSION = '3.31.0';
+const SIMPLE_VERSION = '3.31.1';
 document.getElementById('app-version').textContent = 'v' + SIMPLE_VERSION;
 
 // ===== view history (the browser Back/Forward buttons) =====
diff --git a/frontend/sw.js b/frontend/sw.js
index 10fdfb6..b797ecb 100644
--- a/frontend/sw.js
+++ b/frontend/sw.js
@@ -1,4 +1,4 @@
-const CACHE = 'simple-v455';
+const CACHE = 'simple-v456';
 const URLS = [
   'index.html',
   'help.html',
diff --git a/pyproject.toml b/pyproject.toml
index c1d3f14..73a712f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.31.0"
+version = "3.31.1"
 description = "HTTP REST server wrapping pysim for the SIMple PWA"
 license = { text = "GPL-2.0-or-later" }
 requires-python = ">=3.9"
diff --git a/pysim_simple_server/server.py b/pysim_simple_server/server.py
index 9c67eab..c562f44 100644
--- a/pysim_simple_server/server.py
+++ b/pysim_simple_server/server.py
@@ -37,7 +37,7 @@ from osmocom.tlv import BER_TLV_IE
 from osmocom.utils import rpad
 
 
-VERSION = '3.31.0'
+VERSION = '3.31.1'
 
 MAX_ENVELOPE_SEGMENTS = 5  # max SMS segments for outgoing C-APDU in ENVELOPE
 
diff --git a/setup.sh b/setup.sh
index f6a4044..88e785f 100755
--- a/setup.sh
+++ b/setup.sh
@@ -45,10 +45,11 @@ if command -v pcscd >/dev/null 2>&1; then
     fi
 else
     echo "Note: PC/SC daemon not found. If you use a USB smart card reader,"
-    echo "install pcsc-lite and ccid:"
-    echo "  Debian/Ubuntu: sudo apt install pcscd pcsc-tools"
-    echo "  Arch Linux:    sudo pacman -S pcsc-lite ccid"
-    echo "  Fedora:        sudo dnf install pcsc-lite pcsc-lite-ccid"
+    echo "install pcsc-lite and ccid (plus the PC/SC headers that the"
+    echo "pyscard build needs on Linux):"
+    echo "  Debian/Ubuntu: sudo apt install pcscd pcsc-tools libpcsclite-dev"
+    echo "  Arch Linux:    sudo pacman -S pcsc-lite ccid   (headers included)"
+    echo "  Fedora:        sudo dnf install pcsc-lite pcsc-lite-ccid pcsc-lite-devel"
 fi
 
 echo ""