diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index 5682c63..b6b0f64 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -20,6 +20,22 @@ jobs:
       uses: actions/setup-node@v1
       with:
         node-version: ${{ matrix.node-version }}
+          
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 11
+    
+    - name: Install ANTLR
+      run: |
+        curl -O https://www.antlr.org/download/antlr-4.9.2-complete.jar
+        echo "java -jar $(pwd)/antlr-4.9.2-complete.jar \$@" > antlr4
+        chmod +x antlr4
+        echo "$(pwd)" >> $GITHUB_PATH
+
+    - name: Generate ANTLR Source Files
+      run: antlr4 -Dlanguage=JavaScript FarmExpr.g4 -visitor -o lang
+
     - name: Install dependencies
       run: yarn install
     - name: Compile TypeScript