diff --git a/.github/workflows/translations.yml b/.github/workflows/translations.yml
index d075a75b18..1df3e1bf01 100644
--- a/.github/workflows/translations.yml
+++ b/.github/workflows/translations.yml
@@ -19,16 +19,9 @@ jobs:
               with:
                 python-version: 3.8
 
-            - name: Install calibre dependencies
-              run:
-                  python setup/unix-ci.py install
-
             - name: Install translations dependencies
               run:
-                python -m pip install -U transifex-client sphinx msgpack
-
-            - name: Bootstrap calibre
-              run: python setup/unix-ci.py bootstrap
+                python -m pip install -U transifex-client sphinx
 
             - name: Update translations
               env:
diff --git a/setup/unix-ci.py b/setup/unix-ci.py
index a6063fc30b..3c929b18e0 100644
--- a/setup/unix-ci.py
+++ b/setup/unix-ci.py
@@ -83,6 +83,14 @@ def download_and_decompress(url, dest, compression=None):
     raise SystemExit('Failed to download ' + url)
 
 
+def install_calibre_binary():
+    dest = os.path.expanduser('~/calibre-bin')
+    os.mkdir(dest)
+    # change this to the canonical download url once 5.0 is released
+    download_and_decompress('https://download.calibre-ebook.com/calibre-4.99.12-x86_64.txz', dest, 'J')
+    return os.path.join(dest, 'calibre-debug')
+
+
 def run_python(*args):
     python = os.path.expandvars('$SW/bin/python')
     if len(args) == 1:
@@ -115,7 +123,6 @@ def main():
         run_python('setup.py bootstrap --ephemeral')
 
     elif action == 'pot':
-        install_env()
         transifexrc = '''\
 [https://www.transifex.com]
 api_hostname = https://api.transifex.com
@@ -125,7 +132,8 @@ username = api
 '''.replace('PASSWORD', os.environ['tx'])
         with open(os.path.expanduser('~/.transifexrc'), 'w') as f:
             f.write(transifexrc)
-        run_python('setup.py pot')
+        interpreter = install_calibre_binary()
+        run(interpreter, 'setup.py', 'pot')
 
     elif action == 'test':
         os.environ['CI'] = 'true'