diff --git a/.github/workflow/java-model-diff.yml b/.github/workflow/java-model-diff.yml
new file mode 100644
index 000000000000..ecdf0ac4b83f
--- /dev/null
+++ b/.github/workflow/java-model-diff.yml
@@ -0,0 +1,51 @@
+name: Diff generated Models as Data
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - "java/ql/src/utils/model-generator/**/*.*"
+
+jobs:
+  model-diff:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Clone self (github/codeql) for baseline
+        uses: actions/checkout@v2
+        with:
+          path: codeql-baseline
+          ref: ${{ github.base_ref }}
+      - name: Clone self (github/codeql) with new generator
+        uses: actions/checkout@v2
+        with:
+          path: codeql-current
+          ref: ${{ github.ref }}
+      - name: Show setup
+        run: |
+          echo "Baseline: ${{ github.base_ref }}"
+          echo "Current: ${{ github.ref }}"
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Download CodeQL CLI
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release download --repo "github/codeql-cli-binaries" --pattern "codeql-linux64.zip"
+      - name: Unzip CodeQL CLI
+        run: unzip -d codeql-cli codeql-linux64.zip
+      - name: Build modeled package list
+        run: |
+          mkdir tmp-models
+          SLUG="apache/commons-io"
+          SHORTNAME="commons-io"
+          projectId=`curl -s https://lgtm.com/api/v1.0/projects/g/$SLUG | jq .id`
+          curl -L "https://lgtm.com/api/v1.0/snapshots/$projectId/java" -o $SHORTNAME.zip
+          PATH="$PATH:codeql-cli/codeql" python java/ql/src/utils/model-generator/GenerateFlowModel.py $SHORTNAME.zip tmp-models/$SHORTNAME.qll
+          git add tmp-models/$SHORTNAME.qll
+      - name: Show diff
+        run: |
+          git diff tmp-models/
diff --git a/ruby/extractor/Cargo.toml b/ruby/extractor/Cargo.toml
index efc5a12159d8..3a91da43f86e 100644
--- a/ruby/extractor/Cargo.toml
+++ b/ruby/extractor/Cargo.toml
@@ -9,7 +9,7 @@ edition = "2018"
 [dependencies]
 flate2 = "1.0"
 node-types = { path = "../node-types" }
-tree-sitter = "0.19"
+tree-sitter = "0.20"
 tree-sitter-embedded-template = "0.19"
 tree-sitter-ruby = { git = "https://github.com/tree-sitter/tree-sitter-ruby.git", rev = "bb6a42e42b048627a74a127d3e0184c1eef01de9" }
 clap = "2.33"