diff --git a/java/jsinterop/generator/closure/ClosureJsInteropGenerator.java b/java/jsinterop/generator/closure/ClosureJsInteropGenerator.java
index 7cf8cec..12fdb54 100644
--- a/java/jsinterop/generator/closure/ClosureJsInteropGenerator.java
+++ b/java/jsinterop/generator/closure/ClosureJsInteropGenerator.java
@@ -121,6 +121,9 @@ private Program generateJavaProgram() {
             .build();
 
     compiler.compile(new ArrayList<>(), allSources, createCompilerOptions());
+    if (compiler.getErrorCount() > 0) {
+      throw new GeneratorFailedException();
+    }
 
     GenerationContext ctx =
         GenerationContext.builder()
diff --git a/java/jsinterop/generator/closure/GeneratorFailedException.java b/java/jsinterop/generator/closure/GeneratorFailedException.java
new file mode 100644
index 0000000..f8b853f
--- /dev/null
+++ b/java/jsinterop/generator/closure/GeneratorFailedException.java
@@ -0,0 +1,6 @@
+package jsinterop.generator.closure;
+
+public class GeneratorFailedException
+  extends RuntimeException
+{
+}
diff --git a/java/jsinterop/generator/closure/Runner.java b/java/jsinterop/generator/closure/Runner.java
index 0c6793b..6522742 100644
--- a/java/jsinterop/generator/closure/Runner.java
+++ b/java/jsinterop/generator/closure/Runner.java
@@ -123,6 +123,10 @@ public static void main(String[] args) throws CmdLineException {
     Runner runner = new Runner();
     CmdLineParser parser = new CmdLineParser(runner);
     parser.parseArgument(args);
-    runner.run();
+    try {
+      runner.run();
+    } catch (GeneratorFailedException ignored) {
+      System.exit(1);
+    }
   }
 }