diff --git a/lib/cl/ensure-externals.sh b/lib/cl/ensure-externals.sh
new file mode 100755
index 0000000..0495f03
--- /dev/null
+++ b/lib/cl/ensure-externals.sh
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+if [[ ! -e quicklisp.lisp ]]; then curl -O https://beta.quicklisp.org/quicklisp.lisp; fi
+sbcl --load quicklisp.lisp \
+     --eval "(ignore-errors (quicklisp-quickstart:install :path \"quicklisp/\"))" \
+     --eval "(load \"quicklisp/setup.lisp\")" \
+     --eval "(quicklisp:bundle-systems '(#:puri #:usocket #:closer-mop #:trivial-utf-8 #:ieee-floats #:trivial-gray-streams #:alexandria #:bordeaux-threads #:cl-ppcre #:fiasco #:net.didierverna.clon) :to \"externals/\")" \
+     --eval "(quit)" \
+     --no-userinit
+if [[ ! -e backport-update.zip ]]; then
+    curl -O -L https://github.com/TurtleWarePL/de.setf.thrift/archive/backport-update.zip;
+fi
+mkdir -p lib
+unzip -u backport-update.zip -d lib