diff --git a/app/src/main/res/values/attrs.xml b/app/src/main/res/values/attrs.xml
new file mode 100644
index 0000000..7ce840e
--- /dev/null
+++ b/app/src/main/res/values/attrs.xml
@@ -0,0 +1,12 @@
+<resources>
+
+    <!-- Declare custom theme attributes that allow changing which styles are
+         used for button bars depending on the API level.
+         ?android:attr/buttonBarStyle is new as of API 11 so this is
+         necessary to support previous API levels. -->
+    <declare-styleable name="ButtonBarContainerTheme">
+        <attr name="metaButtonBarStyle" format="reference" />
+        <attr name="metaButtonBarButtonStyle" format="reference" />
+    </declare-styleable>
+
+</resources>