diff --git a/.gitignore b/.gitignore
index 9b26ed04f1..57144f8e25 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
-node_modules
-lib
\ No newline at end of file
+/node_modules
+/lib
+
+# tarball created by 'npm pack'
+/matrix-react-sdk-*.tgz
diff --git a/jenkins.sh b/jenkins.sh
new file mode 100644
index 0000000000..fa99e557d6
--- /dev/null
+++ b/jenkins.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -e
+
+export NVM_DIR="/home/jenkins/.nvm"
+[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"
+nvm use 4
+
+set -x
+
+# install the version of js-sdk provided to us by jenkins
+npm install ./node_modules/matrix-js-sdk-*.tgz
+
+# install the other dependencies
+npm install
+
+# build our tarball
+npm pack