diff --git a/src/main/java/com/nutomic/syncthingandroid/activities/FolderPickerActivity.java b/src/main/java/com/nutomic/syncthingandroid/activities/FolderPickerActivity.java
index 3d539e44..d29a5b87 100644
--- a/src/main/java/com/nutomic/syncthingandroid/activities/FolderPickerActivity.java
+++ b/src/main/java/com/nutomic/syncthingandroid/activities/FolderPickerActivity.java
@@ -234,12 +234,8 @@ public class FolderPickerActivity extends SyncthingActivity
         }
     }
 
-    @SuppressLint("NewApi")
     private void invalidateOptions() {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
-            invalidateOptionsMenu();
-        else
-            supportInvalidateOptionsMenu();
+        invalidateOptionsMenu();
     }
 
     private class FileAdapter extends ArrayAdapter<File> {
diff --git a/src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java b/src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java
index 826ca373..d725b289 100644
--- a/src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java
+++ b/src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java
@@ -148,7 +148,7 @@ public class MainActivity extends SyncthingActivity
                 .setNeutralButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialogInterface, int i) {
-                        sp.edit().putBoolean("first_start", false).commit();
+                        sp.edit().putBoolean("first_start", false).apply();
                     }
                 })
                 .show();
diff --git a/src/main/java/com/nutomic/syncthingandroid/syncthing/SyncthingService.java b/src/main/java/com/nutomic/syncthingandroid/syncthing/SyncthingService.java
index 9dee2fa9..310dfb2c 100644
--- a/src/main/java/com/nutomic/syncthingandroid/syncthing/SyncthingService.java
+++ b/src/main/java/com/nutomic/syncthingandroid/syncthing/SyncthingService.java
@@ -282,7 +282,7 @@ public class SyncthingService extends Service implements
         // Make sure this is also done for existing installs. We can replace this check with
         // {@link #isFirstStart()} after a while.
         if (!sp.getBoolean("default_user_pw_set", false)) {
-            sp.edit().putBoolean("default_user_pw_set", true).commit();
+            sp.edit().putBoolean("default_user_pw_set", true).apply();
             char[] chars =
                     "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz".toCharArray();
             StringBuilder sb = new StringBuilder();
@@ -293,7 +293,7 @@ public class SyncthingService extends Service implements
             String user = Build.MODEL.replaceAll("[^a-zA-Z0-9 ]", "");
             Log.i(TAG, "Generated GUI username and password (username is " + user + ")");
             sp.edit().putString("gui_user", user)
-                     .putString("gui_password", sb.toString()).commit();
+                     .putString("gui_password", sb.toString()).apply();
         }
 
         mDeviceStateHolder = new DeviceStateHolder(SyncthingService.this);
diff --git a/src/main/java/com/nutomic/syncthingandroid/util/ConfigXml.java b/src/main/java/com/nutomic/syncthingandroid/util/ConfigXml.java
index 8c684fd3..44430cb0 100644
--- a/src/main/java/com/nutomic/syncthingandroid/util/ConfigXml.java
+++ b/src/main/java/com/nutomic/syncthingandroid/util/ConfigXml.java
@@ -19,6 +19,7 @@ import org.xml.sax.SAXException;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Locale;
 
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -219,7 +220,7 @@ public class ConfigXml {
                 .getElementsByTagName("folder").item(0);
         String model = Build.MODEL
                 .replace(" ", "_")
-                .toLowerCase()
+                .toLowerCase(Locale.US)
                 .replaceAll("[^a-z0-9_-]", "");
         folder.setAttribute("id", mContext.getString(R.string.default_folder_id, model));
         folder.setAttribute("path", Environment