diff --git a/app/src/main/java/eu/depau/etchdroid/activities/StartActivity.kt b/app/src/main/java/eu/depau/etchdroid/activities/StartActivity.kt
index e9dd21b..9423dde 100644
--- a/app/src/main/java/eu/depau/etchdroid/activities/StartActivity.kt
+++ b/app/src/main/java/eu/depau/etchdroid/activities/StartActivity.kt
@@ -15,14 +15,29 @@ import eu.depau.etchdroid.R
 import eu.depau.etchdroid.StateKeeper
 import eu.depau.etchdroid.enums.FlashMethod
 import eu.depau.etchdroid.kotlin_exts.snackbar
+import eu.depau.etchdroid.utils.DoNotShowAgainDialogFragment
 import kotlinx.android.synthetic.main.activity_start.*
 import java.io.File
 
+
 class StartActivity : ActivityBase() {
     val TAG = "StartActivity"
     val READ_REQUEST_CODE = 42
     val READ_EXTERNAL_STORAGE_PERMISSION = 29
-    var delayedButtonClicked: View? = null
+    val DISMISSED_DIALOGS_PREFS = "dismissed_dialogs"
+    var delayedButtonClicked: Boolean = false
+
+    var shouldShowDMGAlertDialog: Boolean
+        get() {
+            val settings = getSharedPreferences(DISMISSED_DIALOGS_PREFS, 0)
+            return !settings.getBoolean("DMG_beta_alert", false)
+        }
+        set(value) {
+            val settings = getSharedPreferences(DISMISSED_DIALOGS_PREFS, 0)
+            val editor = settings.edit()
+            editor.putBoolean("DMG_beta_alert", !value)
+            editor.apply()
+        }
 
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -30,13 +45,37 @@ class StartActivity : ActivityBase() {
         setContentView(R.layout.activity_start)
     }
 
-    fun onButtonClicked(view: View) {
-        StateKeeper.flashMethod = when (view.id) {
-            R.id.btn_image_raw -> FlashMethod.FLASH_API
-            R.id.btn_image_dmg -> FlashMethod.FLASH_DMG_API
-            else -> null
-        }
+    fun onButtonClicked(view: View) = onButtonClicked(view, true)
 
+    private fun onButtonClicked(view: View?, showDialog: Boolean = true) {
+        if (view != null)
+            StateKeeper.flashMethod = when (view.id) {
+                R.id.btn_image_raw -> FlashMethod.FLASH_API
+                R.id.btn_image_dmg -> FlashMethod.FLASH_DMG_API
+                else -> null
+            }
+
+        if (StateKeeper.flashMethod != FlashMethod.FLASH_DMG_API || !shouldShowDMGAlertDialog || !showDialog)
+            showFilePicker()
+        else
+            showDMGBetaAlertDialog()
+    }
+
+    fun showDMGBetaAlertDialog() {
+        val dialogFragment = DoNotShowAgainDialogFragment()
+        dialogFragment.title = getString(R.string.here_be_dragons)
+        dialogFragment.message = getString(R.string.dmg_alert_dialog_text)
+        dialogFragment.closeButton = getString(R.string.i_understand)
+        dialogFragment.listener = object : DoNotShowAgainDialogFragment.DialogListener {
+            override fun onDialogClose(dialog: DoNotShowAgainDialogFragment, showAgain: Boolean) {
+                shouldShowDMGAlertDialog = showAgain
+                showFilePicker()
+            }
+        }
+        dialogFragment.show(supportFragmentManager, "DMGBetaAlertDialogFragment")
+    }
+
+    fun showFilePicker() {
         when (StateKeeper.flashMethod) {
             FlashMethod.FLASH_API -> {
                 val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)
@@ -62,7 +101,7 @@ class StartActivity : ActivityBase() {
                         nextStep()
                     }
                 } else {
-                    delayedButtonClicked = view
+                    delayedButtonClicked = true
                 }
             }
             FlashMethod.FLASH_UNETBOOTIN -> {
@@ -95,8 +134,8 @@ class StartActivity : ActivityBase() {
     override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
         when (requestCode) {
             READ_EXTERNAL_STORAGE_PERMISSION -> {
-                if (delayedButtonClicked != null)
-                    onButtonClicked(delayedButtonClicked!!)
+                if (delayedButtonClicked)
+                    onButtonClicked(null, showDialog = false)
                 return
             }
             else -> {
diff --git a/app/src/main/java/eu/depau/etchdroid/utils/DoNotShowAgainDialogFragment.kt b/app/src/main/java/eu/depau/etchdroid/utils/DoNotShowAgainDialogFragment.kt
new file mode 100644
index 0000000..4b6c6a0
--- /dev/null
+++ b/app/src/main/java/eu/depau/etchdroid/utils/DoNotShowAgainDialogFragment.kt
@@ -0,0 +1,40 @@
+package eu.depau.etchdroid.utils
+
+import android.app.Dialog
+import android.os.Bundle
+import android.view.LayoutInflater
+import androidx.appcompat.app.AlertDialog
+import androidx.fragment.app.DialogFragment
+import eu.depau.etchdroid.R
+import kotlinx.android.synthetic.main.do_not_show_again.view.*
+
+
+class DoNotShowAgainDialogFragment() : DialogFragment() {
+    var title: String? = null
+    var closeButton: String? = null
+    var message: String? = null
+    var listener: DialogListener? = null
+
+    interface DialogListener {
+        fun onDialogClose(dialog: DoNotShowAgainDialogFragment, showAgain: Boolean)
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        // Build the dialog and set up the button click handlers
+        val builder = AlertDialog.Builder(activity!!)
+        val inflater = LayoutInflater.from(this.context)
+        val dnsaLayout = inflater.inflate(R.layout.do_not_show_again, null)
+        val doNotShowAgainCB = dnsaLayout.do_not_show_again
+
+        builder
+                .setTitle(title)
+                .setMessage(message)
+                .setView(dnsaLayout)
+                .setPositiveButton(closeButton) { _, _ ->
+                    listener?.onDialogClose(this@DoNotShowAgainDialogFragment, !doNotShowAgainCB.isChecked)
+                }
+
+        return builder.create()
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/do_not_show_again.xml b/app/src/main/res/layout/do_not_show_again.xml
new file mode 100644
index 0000000..1c594c7
--- /dev/null
+++ b/app/src/main/res/layout/do_not_show_again.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+              android:id="@+id/layout_root"
+              android:layout_width="fill_parent"
+              android:layout_height="fill_parent"
+              android:orientation="horizontal"
+              android:padding="10dp" >
+    <CheckBox
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:id="@+id/do_not_show_again"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/do_not_show_again"
+        android:layout_marginStart="10dp">
+    </CheckBox>
+</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index f1bca8e..47eee53 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -91,4 +91,8 @@
     <string name="write_apple_dmg">Write Apple® DMG image</string>
     <string name="dmg_image_desc">Restore an image created with macOS Disk Utility</string>
     <string name="no_usb_drives_detected">No USB drives detected</string>
+    <string name="do_not_show_again">Do not show again</string>
+    <string name="here_be_dragons">Here be dragons</string>
+    <string name="i_understand">I understand, continue</string>
+    <string name="dmg_alert_dialog_text">While in most cases DMG images can be restored just fine, sometimes there may be inconsistencies. You\'ve been warned.</string>
 </resources>