diff --git a/k9mail/src/main/java/com/fsck/k9/ui/dialog/AutocryptPreferEncryptDialog.java b/k9mail/src/main/java/com/fsck/k9/ui/dialog/AutocryptPreferEncryptDialog.java
deleted file mode 100644
index b97dccf43..000000000
--- a/k9mail/src/main/java/com/fsck/k9/ui/dialog/AutocryptPreferEncryptDialog.java
+++ /dev/null
@@ -1,76 +0,0 @@
-package com.fsck.k9.ui.dialog;
-
-
-import android.annotation.SuppressLint;
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.content.Context;
-import android.content.DialogInterface;
-import android.text.method.LinkMovementMethod;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.View.OnClickListener;
-import android.widget.CheckBox;
-import android.widget.TextView;
-
-import com.fsck.k9.R;
-
-
-public class AutocryptPreferEncryptDialog extends AlertDialog implements OnClickListener {
-
-    private final CheckBox preferEncryptCheckbox;
-    private final OnPreferEncryptChangedListener onPreferEncryptChangedListener;
-
-    private boolean preferEncryptEnabled;
-
-    public AutocryptPreferEncryptDialog(Context context, boolean preferEncryptEnabled,
-            OnPreferEncryptChangedListener onPreferEncryptChangedListener) {
-        super(context);
-
-        this.onPreferEncryptChangedListener = onPreferEncryptChangedListener;
-        this.preferEncryptEnabled = preferEncryptEnabled;
-
-        LayoutInflater inflater = LayoutInflater.from(context);
-
-        @SuppressLint("InflateParams")
-        View contentView = inflater.inflate(R.layout.dialog_autocrypt_prefer_encrypt, null);
-
-        TextView learnMoreText = (TextView) contentView.findViewById(R.id.prefer_encrypt_learn_more);
-        makeTextViewLinksClickable(learnMoreText);
-
-        preferEncryptCheckbox = (CheckBox) contentView.findViewById(R.id.prefer_encrypt_check);
-        preferEncryptCheckbox.setChecked(preferEncryptEnabled);
-
-        contentView.findViewById(R.id.prefer_encrypt).setOnClickListener(this);
-
-        // TODO add autocrypt logo?
-        // setIcon(R.drawable.autocrypt);
-        setView(contentView);
-        setButton(Dialog.BUTTON_POSITIVE, context.getString(R.string.done_action), new OnClickListener() {
-            @Override
-            public void onClick(DialogInterface dialogInterface, int i) {
-                cancel();
-            }
-        });
-    }
-
-    @Override
-    public void onClick(View v) {
-        toggleCheck();
-    }
-
-    private void toggleCheck() {
-        preferEncryptEnabled = !preferEncryptEnabled;
-        preferEncryptCheckbox.setChecked(preferEncryptEnabled);
-
-        onPreferEncryptChangedListener.onPreferEncryptChanged(preferEncryptEnabled);
-    }
-
-    public interface OnPreferEncryptChangedListener {
-        void onPreferEncryptChanged(boolean enabled);
-    }
-
-    private void makeTextViewLinksClickable(TextView textView) {
-        textView.setMovementMethod(LinkMovementMethod.getInstance());
-    }
-}
diff --git a/k9mail/src/main/java/com/fsck/k9/ui/settings/account/AutocryptPreferEncryptDialogFragment.kt b/k9mail/src/main/java/com/fsck/k9/ui/settings/account/AutocryptPreferEncryptDialogFragment.kt
index 8784bf0e5..65e4c8b78 100644
--- a/k9mail/src/main/java/com/fsck/k9/ui/settings/account/AutocryptPreferEncryptDialogFragment.kt
+++ b/k9mail/src/main/java/com/fsck/k9/ui/settings/account/AutocryptPreferEncryptDialogFragment.kt
@@ -1,10 +1,17 @@
 package com.fsck.k9.ui.settings.account
 
+import android.annotation.SuppressLint
 import android.app.Dialog
 import android.os.Bundle
 import android.support.v4.app.DialogFragment
+import android.support.v7.app.AlertDialog
 import android.support.v7.preference.DialogPreference
-import com.fsck.k9.ui.dialog.AutocryptPreferEncryptDialog
+import android.text.method.LinkMovementMethod
+import android.view.LayoutInflater
+import android.view.View
+import android.widget.CheckBox
+import android.widget.TextView
+import com.fsck.k9.R
 
 class AutocryptPreferEncryptDialogFragment : DialogFragment() {
     private val preference: AutocryptPreferEncryptPreference by lazy {
@@ -16,11 +23,30 @@ class AutocryptPreferEncryptDialogFragment : DialogFragment() {
 
 
     override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
-        val autocryptPreferEncryptMutual = preference.isChecked
+        @SuppressLint("InflateParams")
+        val view = LayoutInflater.from(context).inflate(R.layout.dialog_autocrypt_prefer_encrypt, null)
 
-        return AutocryptPreferEncryptDialog(context, autocryptPreferEncryptMutual) { newValue ->
-            preference.userChangedValue(newValue)
+        view.findViewById<TextView>(R.id.prefer_encrypt_learn_more).makeLinksClickable()
+
+        val preferEncryptCheckbox = view.findViewById<CheckBox>(R.id.prefer_encrypt_check).apply {
+            isChecked = preference.isChecked
         }
+
+        view.findViewById<View>(R.id.prefer_encrypt).setOnClickListener {
+            preferEncryptCheckbox.performClick()
+            preference.userChangedValue(preferEncryptCheckbox.isChecked)
+        }
+
+        return AlertDialog.Builder(requireContext())
+                // TODO add autocrypt logo?
+                //.setIcon(R.drawable.autocrypt)
+                .setView(view)
+                .setPositiveButton(R.string.done_action, null)
+                .create()
+    }
+
+    private fun TextView.makeLinksClickable() {
+        this.movementMethod = LinkMovementMethod.getInstance()
     }