diff --git a/jenkins.sh b/jenkins.sh
index 2fd3048f..a421c4d2 100755
--- a/jenkins.sh
+++ b/jenkins.sh
@@ -5,6 +5,10 @@ nvm use 4
 npm install
 (cd node_modules/matrix-react-sdk && npm run build) # npm doesn't do this when dependencies point at github.com >:(
 npm run build # Dumps artificats to /vector
+
+# gzip up ./vector
 rm vector-*.tar.gz || true # rm previous artifacts without failing if it doesn't exist
-REACT_SHA=$(git --git-dir node_modules/matrix-react-sdk/.git rev-parse --short=12 HEAD) # use the ACTUAL SHA rather than assume develop
-tar -zcvhf vector-$GIT_COMMIT-react-$REACT_SHA.tar.gz vector #g[z]ip, [c]reate archive, [v]erbose, [f]ilename, [h]ard-dereference (do not archive symlinks)
+REACT_SHA=$(grep 'gitHead' node_modules/matrix-react-sdk/package.json | cut -d \" -f 4 | head -c 12) # node_modules deps from 'npm install' don't have a .git dir so can't rev-parse.
+JSSDK_SHA=$(grep 'gitHead' node_modules/matrix-js-sdk/package.json | cut -d \" -f 4 | head -c 12)    # But they do set the commit in package.json under 'gitHead' which we're grabbing here.
+VECTOR_SHA=$(git rev-parse --short=12 HEAD) # use the ACTUAL SHA rather than assume develop
+tar -zcvhf vector-$VECTOR_SHA-react-$REACT_SHA-js-$JSSDK_SHA.tar.gz vector #g[z]ip, [c]reate archive, [v]erbose, [f]ilename, [h]ard-dereference (do not archive symlinks)