--- a/mobile/android/base/java/org/mozilla/gecko/GeckoFontScaleListener.java
+++ b/mobile/android/base/java/org/mozilla/gecko/GeckoFontScaleListener.java
@@ -124,32 +124,35 @@ public class GeckoFontScaleListener
         if (useSystemFontScale) {
             start();
         } else {
             stop();
         }
     }
 
     private void migrateOldSetting(final SharedPreferences prefs) {
+        Log.d(LOGTAG, "migrate old font size setting");
         PrefsHelper.getPref(PREF_FONT_INFLATION, new PrefsHelper.PrefHandlerBase() {
             @Override
             public void prefValue(String pref, int value) {
                 // The first setting step above "Tiny" used to correspond to a value of 80.
                 prefs.edit().putBoolean(GeckoPreferences.PREFS_SYSTEM_FONT_SIZE, (value > 60)).apply();
             }
         });
     }
 
     @Override
     public void onChange(boolean selfChange) {
+        Log.d(LOGTAG, "system setting changed");
         onSystemFontScaleChange(mApplicationContext.getContentResolver(), false);
     }
 
     @UiThread // According to the docs.
     @Override
     public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
         if (!GeckoPreferences.PREFS_SYSTEM_FONT_SIZE.equals(key)) {
             return;
         }
 
+        Log.d(LOGTAG, "shared pref changed");
         onPrefChange(sharedPreferences);
     }
 }