diff --git a/.github/workflows/test-and-publish.yaml b/.github/workflows/test-and-publish.yaml
index 260f317a..042d9386 100644
--- a/.github/workflows/test-and-publish.yaml
+++ b/.github/workflows/test-and-publish.yaml
@@ -38,7 +38,7 @@ jobs:
         uses: actions/cache@v3
         with:
           path: |
-            ./firefox-102.2.0/*
+            ./firefox-source/*
             ./_spidermonkey_install/*
           key: ${{ runner.os }}-spidermonkey
       - name: Build-Library
diff --git a/.gitignore b/.gitignore
index f48e7479..cfb07c4c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,9 +5,7 @@ bin/
 lib/*
 .pytest_cache
 .DS_Store
-firefox-102.2.0*
-firefox-102.2.0/*
-firefox-*/*
+firefox-*.tar.xz
 firefox-*/
 tests/__pycache__/*
 tests/python/__pycache__/*
diff --git a/setup.sh b/setup.sh
index 827da61f..137685c6 100755
--- a/setup.sh
+++ b/setup.sh
@@ -14,16 +14,13 @@ sudo curl --proto '=https' --tlsv1.3 https://sh.rustup.rs -sSf | sh -s -- -y #in
 echo "Done installing dependencies"
 
 echo "Downloading spidermonkey source code"
-wget -c -q https://ftp.mozilla.org/pub/firefox/releases/102.2.0esr/source/firefox-102.2.0esr.source.tar.xz
-tar xf firefox-102.2.0esr.source.tar.xz
+wget -c -q https://ftp.mozilla.org/pub/firefox/releases/102.11.0esr/source/firefox-102.11.0esr.source.tar.xz
+mkdir -p firefox-source
+tar xf firefox-102.11.0esr.source.tar.xz -C firefox-source --strip-components=1 # strip the root folder
 echo "Done downloading spidermonkey source code"
 
 echo "Building spidermonkey"
-cd firefox-102.2.0/python/mozbuild/mozbuild
-# the build system breaks on Python 3.11 (`io.open()` no longer accepts 'U' in the file mode)
-sed -i 's/"rU"/"r"/g' util.py preprocessor.py action/process_define_files.py backend/base.py
-cd -
-cd firefox-102.2.0/js
+cd firefox-source/js
 sed -i 's/bool Unbox/JS_PUBLIC_API bool Unbox/g' ./public/Class.h           # need to manually add JS_PUBLIC_API to js::Unbox until it gets fixed in Spidermonkey
 sed -i 's/bool js::Unbox/JS_PUBLIC_API bool js::Unbox/g' ./src/vm/JSObject.cpp  # same here
 cd src