diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index 5f46eb92..1a033ed5 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -36,7 +36,7 @@ class Main(
     private val input: InputStream,
     private val out: PrintStream,
     private val err: PrintStream,
-    args: Array<String>
+    private val args: Array<String>
 ) {
   companion object {
     @JvmStatic
@@ -69,9 +69,13 @@ class Main(
     }
   }
 
-  private val parsedArgs: ParsedArgs = ParsedArgs.processArgs(err, args)
+
 
   fun run(): Int {
+    val parsedArgs = when (val argParseResult = ParsedArgs.processArgs(err, args)) {
+      is ArgParseResult.Ok -> argParseResult.parsedArgs
+      is ArgParseResult.Error -> exitFatal(argParseResult.errorMessage, 1)
+    }
     if (parsedArgs.fileNames.isEmpty()) {
       err.println(
           "Usage: ktfmt [--dropbox-style | --google-style | --kotlinlang-style] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...")
@@ -81,7 +85,7 @@ class Main(
 
     if (parsedArgs.fileNames.size == 1 && parsedArgs.fileNames[0] == "-") {
       return try {
-        val alreadyFormatted = format(null)
+        val alreadyFormatted = format(null,parsedArgs)
         if (!alreadyFormatted && parsedArgs.setExitIfChanged) 1 else 0
       } catch (e: Exception) {
         1
@@ -107,7 +111,7 @@ class Main(
     val retval = AtomicInteger(0)
     files.parallelStream().forEach {
       try {
-        if (!format(it) && parsedArgs.setExitIfChanged) {
+        if (!format(it, parsedArgs) && parsedArgs.setExitIfChanged) {
           retval.set(1)
         }
       } catch (e: Exception) {
@@ -126,17 +130,17 @@ class Main(
    * @param file The file to format. If null, the code is read from <stdin>.
    * @return true iff input is valid and already formatted.
    */
-  private fun format(file: File?): Boolean {
-    val fileName = file?.toString() ?: parsedArgs.stdinName ?: "<stdin>"
+  private fun format(file: File?, args: ParsedArgs): Boolean {
+    val fileName = file?.toString() ?: args.stdinName ?: "<stdin>"
     try {
       val bytes = if (file == null) input else FileInputStream(file)
       val code = BufferedReader(InputStreamReader(bytes, UTF_8)).readText()
-      val formattedCode = Formatter.format(parsedArgs.formattingOptions, code)
+      val formattedCode = Formatter.format(args.formattingOptions, code)
       val alreadyFormatted = code == formattedCode
 
       // stdin
       if (file == null) {
-        if (parsedArgs.dryRun) {
+        if (args.dryRun) {
           if (!alreadyFormatted) {
             out.println(fileName)
           }
@@ -146,7 +150,7 @@ class Main(
         return alreadyFormatted
       }
 
-      if (parsedArgs.dryRun) {
+      if (args.dryRun) {
         if (!alreadyFormatted) {
           out.println(fileName)
         }
@@ -173,4 +177,11 @@ class Main(
       throw e
     }
   }
+
+  fun exitFatal(message: String, returnCode: Int): Nothing {
+    err.println(message)
+    exitProcess(returnCode)
+  }
+
 }
+
diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index e0009f7b..6670c18b 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -39,11 +39,11 @@ data class ParsedArgs(
 ) {
   companion object {
 
-    fun processArgs(err: PrintStream, args: Array<String>): ParsedArgs {
+    fun processArgs(err: PrintStream, args: Array<String>): ArgParseResult {
       if (args.size == 1 && args[0].startsWith("@")) {
-        return parseOptions(err, File(args[0].substring(1)).readLines(UTF_8).toTypedArray())
+        return ArgParseResult.Ok(parseOptions(err, File(args[0].substring(1)).readLines(UTF_8).toTypedArray()))
       } else {
-        return parseOptions(err, args)
+        return ArgParseResult.Ok(parseOptions(err, args))
       }
     }
 
@@ -90,3 +90,8 @@ data class ParsedArgs(
     }
   }
 }
+
+sealed interface ArgParseResult {
+  data class Ok(val parsedArgs: ParsedArgs): ArgParseResult
+  data class Error(val errorMessage: String): ArgParseResult
+}
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index 9f0919bf..77539663 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -177,7 +177,10 @@ class ParsedArgsTest {
     val file = root.resolve("existing-file")
     file.writeText("--google-style\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
 
-    val parsed = ParsedArgs.processArgs(PrintStream(out), arrayOf("@" + file.absolutePath))
+    val result = ParsedArgs.processArgs(PrintStream(out), arrayOf("@" + file.absolutePath))
+    assertThat(result).isInstanceOf(ArgParseResult.Ok::class.java)
+
+    val parsed = (result as ArgParseResult.Ok).parsedArgs
 
     assertThat(parsed.formattingOptions).isEqualTo(Formatter.GOOGLE_FORMAT)
     assertThat(parsed.dryRun).isTrue()