Update

core/src/main/java/com/afollestad/materialdialogs/GravityEnum.java

@@ -1,5 +1,6 @@
 package com.afollestad.materialdialogs;
 
+import android.annotation.TargetApi;
 import android.os.Build;
 import android.view.Gravity;
 import android.view.View;
@@ -22,6 +23,7 @@ public enum GravityEnum {
         }
     }
 
+    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
     public int getTextAlignment() {
         switch (this) {
             case CENTER:

core/src/main/java/com/afollestad/materialdialogs/MaterialDialog.java

@@ -43,6 +43,7 @@ import android.widget.TextView;
 import com.afollestad.materialdialogs.internal.MDButton;
 import com.afollestad.materialdialogs.internal.MDRootLayout;
 import com.afollestad.materialdialogs.internal.MDTintHelper;
+import com.afollestad.materialdialogs.internal.ThemeSingleton;
 import com.afollestad.materialdialogs.util.DialogUtils;
 import com.afollestad.materialdialogs.util.TypefaceHelper;
 

core/src/main/java/com/afollestad/materialdialogs/ThemeSingleton.java → core/src/main/java/com/afollestad/materialdialogs/internal/ThemeSingleton.java

@@ -1,10 +1,12 @@
-package com.afollestad.materialdialogs;
+package com.afollestad.materialdialogs.internal;
 
 import android.content.res.ColorStateList;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.ColorInt;
 import android.support.annotation.DrawableRes;
 
+import com.afollestad.materialdialogs.GravityEnum;
+
 /**
  * Use of this is discouraged for now; for internal use only. See the Global Theming section of the README.
  */

sample/src/main/java/com/afollestad/materialdialogssample/MainActivity.java

@@ -28,7 +28,7 @@ import com.afollestad.materialdialogs.DialogAction;
 import com.afollestad.materialdialogs.GravityEnum;
 import com.afollestad.materialdialogs.MaterialDialog;
 import com.afollestad.materialdialogs.Theme;
-import com.afollestad.materialdialogs.ThemeSingleton;
+import com.afollestad.materialdialogs.internal.ThemeSingleton;
 import com.afollestad.materialdialogs.commons.color.CircleView;
 import com.afollestad.materialdialogs.commons.color.ColorChooserDialog;
 import com.afollestad.materialdialogs.commons.simplelist.MaterialSimpleListAdapter;