diff --git a/app/src/main/res/values-nl/strings.xml b/app/src/main/res/values-nl/strings.xml
index c25c4f4..e3a7129 100644
--- a/app/src/main/res/values-nl/strings.xml
+++ b/app/src/main/res/values-nl/strings.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<resources>
+<resources xmlns:tools="http://schemas.android.com/tools" tools:locale="nl">
     <string name="app_name">THEOplayer Open Video UI voor Android Demo</string>
     <string name="theoplayer_ui_btn_play">Afspelen</string>
     <string name="theoplayer_ui_btn_pause">Pauzeren</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index d696adc..611cf98 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,4 +1,4 @@
-<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+<resources xmlns:tools="http://schemas.android.com/tools" xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2" tools:locale="en">
     <string name="app_name">THEOplayer Open Video UI for Android Demo</string>
 
     <!-- Copied from Open Video UI for Android -->
diff --git a/ui/src/main/res/values/strings.xml b/ui/src/main/res/values/strings.xml
index 4e7355e..98c3479 100644
--- a/ui/src/main/res/values/strings.xml
+++ b/ui/src/main/res/values/strings.xml
@@ -1,4 +1,4 @@
-<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+<resources xmlns:tools="http://schemas.android.com/tools" xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2" tools:locale="en">
     <string name="theoplayer_ui_btn_play">Play</string>
     <string name="theoplayer_ui_btn_pause">Pause</string>
     <string name="theoplayer_ui_btn_replay">Replay</string>